72643728 has 40 divisors (see below), whose sum is σ = 192739648. Its totient is φ = 23559552.

The previous prime is 72643709. The next prime is 72643733. The reversal of 72643728 is 82734627.

It is a super-2 number, since 2×72643728² = 10554222435475968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18676 + ... + 22227.

Almost surely, 2^72643728 is an apocalyptic number.

It is an amenable number.

72643728 is an abundant number, since it is smaller than the sum of its proper divisors (120095920).

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

72643728 is a wasteful number, since it uses less digits than its factorization.

72643728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40951 (or 40945 counting only the distinct ones).

The product of its digits is 112896, while the sum is 39.

The square root of 72643728 is about 8523.1290028956. The cubic root of 72643728 is about 417.2529103151.

The spelling of 72643728 in words is "seventy-two million, six hundred forty-three thousand, seven hundred twenty-eight".