72172156 has 24 divisors (see below), whose sum is σ = 144589536. Its totient is φ = 30878400.

The previous prime is 72172141. The next prime is 72172169. The reversal of 72172156 is 65127127.

It is a congruent number.

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, 17790 + ... + 21466.

It is an arithmetic number, because the mean of its divisors is an integer number (6024564).

Almost surely, 2^72172156 is an apocalyptic number.

It is an amenable number.

72172156 is an abundant number, since it is smaller than the sum of its proper divisors (72417380).

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

72172156 is a wasteful number, since it uses less digits than its factorization.

72172156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4389 (or 4387 counting only the distinct ones).

The product of its digits is 5880, while the sum is 31.

The square root of 72172156 is about 8495.4197071128. The cubic root of 72172156 is about 416.3480737564.

The spelling of 72172156 in words is "seventy-two million, one hundred seventy-two thousand, one hundred fifty-six".