72561328 has 40 divisors (see below), whose sum is σ = 165862400. Its totient is φ = 30093120.

The previous prime is 72561317. The next prime is 72561341. The reversal of 72561328 is 82316527.

It is a happy number.

It is a super-2 number, since 2×72561328² = 10530292642247168, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72561293 and 72561302.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6978 + ... + 13921.

It is an arithmetic number, because the mean of its divisors is an integer number (4146560).

Almost surely, 2^72561328 is an apocalyptic number.

It is an amenable number.

72561328 is an abundant number, since it is smaller than the sum of its proper divisors (93301072).

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

72561328 is a wasteful number, since it uses less digits than its factorization.

72561328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20945 (or 20939 counting only the distinct ones).

The product of its digits is 20160, while the sum is 34.

The square root of 72561328 is about 8518.2937258585. The cubic root of 72561328 is about 417.0950868815.

The spelling of 72561328 in words is "seventy-two million, five hundred sixty-one thousand, three hundred twenty-eight".