72657664 has 36 divisors (see below), whose sum is σ = 145581856. Its totient is φ = 36191232.

The previous prime is 72657631. The next prime is 72657701. The reversal of 72657664 is 46675627.

It is a super-2 number, since 2×72657664² = 10558272275873792, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 72657664.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118222 + ... + 118834.

Almost surely, 2^72657664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72657664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72790928).

72657664 is an abundant number, since it is smaller than the sum of its proper divisors (72924192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72657664 is an equidigital number, since it uses as much as digits as its factorization.

72657664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092 (or 1078 counting only the distinct ones).

The product of its digits is 423360, while the sum is 43.

The square root of 72657664 is about 8523.9465038209. The cubic root of 72657664 is about 417.2795905939.

The spelling of 72657664 in words is "seventy-two million, six hundred fifty-seven thousand, six hundred sixty-four".