60 is a highly composite number. Because it is the sum of its unitary divisors (excluding itself), it is a unitary perfect number,and it is an abundant number with an abundance of 48. Being ten times a perfect number, it is a semiperfect number. 60 is a Twin-prime sum of the fifth pair of twin-primes, 29 + 31. It is the smallest number divisible by the numbers 1 to 6: there is no smaller number divisible by the numbers 1 to 5 since any number divisible by 2 and 3 must also be divisible by 6. It is the smallest number with exactly 12 divisors. Having 12 as one of those divisors, 60 is also a refactorable number. It is one of seven integers that have more divisors than any number less than twice itself (sequence A072938 in the OEIS), one of six that are also lowest common multiple of a consecutive set of integers from 1, and one of six that are divisors of every highly composite number higher than itself. (sequence A106037 in the OEIS)