72172328 has 8 divisors (see below), whose sum is σ = 135323130. Its totient is φ = 36086160.

The previous prime is 72172319. The next prime is 72172343. The reversal of 72172328 is 82327127.

It can be written as a sum of positive squares in only one way, i.e., 67601284 + 4571044 = 8222^2 + 2138^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 72172294 and 72172303.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4510763 + ... + 4510778.

Almost surely, 2^72172328 is an apocalyptic number.

It is an amenable number.

72172328 is a deficient number, since it is larger than the sum of its proper divisors (63150802).

72172328 is a wasteful number, since it uses less digits than its factorization.

72172328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9021547 (or 9021543 counting only the distinct ones).

The product of its digits is 9408, while the sum is 32.

The square root of 72172328 is about 8495.4298302087. The cubic root of 72172328 is about 416.3484045017.

The spelling of 72172328 in words is "seventy-two million, one hundred seventy-two thousand, three hundred twenty-eight".