diff --git a/spring-core/src/main/java/org/springframework/core/annotation/SynthesizedMergedAnnotationInvocationHandler.java b/spring-core/src/main/java/org/springframework/core/annotation/SynthesizedMergedAnnotationInvocationHandler.java
index 0e977696c65..24c21acf6af 100644
--- a/spring-core/src/main/java/org/springframework/core/annotation/SynthesizedMergedAnnotationInvocationHandler.java
+++ b/spring-core/src/main/java/org/springframework/core/annotation/SynthesizedMergedAnnotationInvocationHandler.java
@@ -137,14 +137,20 @@ final class SynthesizedMergedAnnotationInvocationHandler<A extends Annotation> i
 		String string = this.string;
 		if (string == null) {
 			StringBuilder builder = new StringBuilder("@").append(getName(this.type)).append('(');
-			for (int i = 0; i < this.attributes.size(); i++) {
-				Method attribute = this.attributes.get(i);
-				if (i > 0) {
-					builder.append(", ");
+			if (this.attributes.size() == 1 && this.attributes.get(0).getName().equals(MergedAnnotation.VALUE)) {
+				// Don't prepend "value=" for an annotation that only declares a "value" attribute.
+				builder.append(toString(getAttributeValue(this.attributes.get(0))));
+			}
+			else {
+				for (int i = 0; i < this.attributes.size(); i++) {
+					Method attribute = this.attributes.get(i);
+					if (i > 0) {
+						builder.append(", ");
+					}
+					builder.append(attribute.getName());
+					builder.append('=');
+					builder.append(toString(getAttributeValue(attribute)));
 				}
-				builder.append(attribute.getName());
-				builder.append('=');
-				builder.append(toString(getAttributeValue(attribute)));
 			}
 			builder.append(')');
 			string = builder.toString();
@@ -187,7 +193,7 @@ final class SynthesizedMergedAnnotationInvocationHandler<A extends Annotation> i
 			return '\'' + value.toString() + '\'';
 		}
 		if (type == Byte.class) {
-			return String.format("(byte) 0x%02X", value);
+			return String.format("(byte)0x%02x", value);
 		}
 		if (type == Long.class) {
 			return Long.toString((Long) value) + 'L';
@@ -196,7 +202,7 @@ final class SynthesizedMergedAnnotationInvocationHandler<A extends Annotation> i
 			return Float.toString((Float) value) + 'f';
 		}
 		if (type == Double.class) {
-			return Double.toString((Double) value) + 'd';
+			return Double.toString((Double) value);
 		}
 		if (value instanceof Enum<?> e) {
 			return e.name();
diff --git a/spring-core/src/test/java/org/springframework/core/annotation/MergedAnnotationsTests.java b/spring-core/src/test/java/org/springframework/core/annotation/MergedAnnotationsTests.java
index 480f5ad2d09..276fb7167c7 100644
--- a/spring-core/src/test/java/org/springframework/core/annotation/MergedAnnotationsTests.java
+++ b/spring-core/src/test/java/org/springframework/core/annotation/MergedAnnotationsTests.java
@@ -2011,9 +2011,9 @@ class MergedAnnotationsTests {
 
 		// The unsynthesized annotation for handleMappedWithSamePathAndValueAttributes()
 		// should produce almost the same toString() results as synthesized annotations for
-		// handleMappedWithPathAttribute() on Java 9 or higher; however, due to multiple changes
-		// in the JDK's toString() implementation for annotations in JDK 9, 14, and 19,
-		// we do not test the JDK implementation.
+		// handleMappedWithPathAttribute(); however, due to multiple changes in the JDK's
+		// toString() implementation for annotations in JDK 19 and higher, we do not test
+		// the JDK implementation.
 		// assertToStringForWebMappingWithPathAndValue(webMappingWithPathAndValue);
 
 		assertToStringForWebMappingWithPathAndValue(synthesizedWebMapping1);
@@ -2021,7 +2021,7 @@ class MergedAnnotationsTests {
 	}
 
 	private void assertToStringForWebMappingWithPathAndValue(RequestMapping webMapping) {
-		assertThat(webMapping.toString())
+		assertThat(webMapping).asString()
 				.startsWith("@org.springframework.core.annotation.MergedAnnotationsTests.RequestMapping(")
 				.contains(
 					// Strings
@@ -2034,7 +2034,7 @@ class MergedAnnotationsTests {
 					"clazz=org.springframework.core.annotation.MergedAnnotationsTests.RequestMethod.class",
 					"classes={int[][].class, org.springframework.core.annotation.MergedAnnotationsTests.RequestMethod[].class}",
 					// Bytes
-					"byteValue=(byte) 0xFF", "bytes={(byte) 0xFF}",
+					"byteValue=(byte)0xff", "bytes={(byte)0xff}",
 					// Shorts
 					"shortValue=9876", "shorts={9876}",
 					// Longs
@@ -2042,11 +2042,24 @@ class MergedAnnotationsTests {
 					// Floats
 					"floatValue=3.14f", "floats={3.14f}",
 					// Doubles
-					"doubleValue=99.999d", "doubles={99.999d}"
+					"doubleValue=99.999", "doubles={99.999}"
 				)
 				.endsWith(")");
 	}
 
+	@Test  // gh-36417
+	void toStringForSynthesizedAnnotationsWithSingleValueAttributes() {
+		MyRepeatable myRepeatable = MergedAnnotations.from(SingleMyRepeatableClass.class)
+				.get(MyRepeatable.class).synthesize();
+		assertThat(myRepeatable).asString()
+				.isEqualTo("@%s(\"meta\")", MyRepeatable.class.getCanonicalName());
+
+		ValueAttribute valueAttribute = MergedAnnotations.from(ValueAttributeMetaMetaClass.class)
+				.get(ValueAttribute.class).synthesize();
+		assertThat(valueAttribute).asString()
+				.isEqualTo("@%s({\"FromValueAttributeMeta\"})", ValueAttribute.class.getCanonicalName());
+	}
+
 	@Test
 	void equalsForSynthesizedAnnotations() throws Exception {
 		Method methodWithPath = WebController.class.getMethod("handleMappedWithPathAttribute");
@@ -3085,6 +3098,16 @@ class MergedAnnotationsTests {
 	static class MyRepeatableClass {
 	}
 
+	@Retention(RetentionPolicy.RUNTIME)
+	@Inherited
+	@MyRepeatable("meta")
+	@interface SingleMyRepeatable {
+	}
+
+	@SingleMyRepeatable
+	static class SingleMyRepeatableClass {
+	}
+
 	static class SubMyRepeatableClass extends MyRepeatableClass {
 	}