50

is the integer between.

Math features

 * 50 is an even number.
 * 50 is a Harshad number.
 * 50 is a deficient number.
 * 50 is part of 3 Pythagorean triples: (30, 40, 50), (50, 120, 130) and (14, 48, 50).
 * 50 is a factor of 100.