72557361 has 6 divisors (see below), whose sum is σ = 104805090. Its totient is φ = 48371568.

The previous prime is 72557357. The next prime is 72557369. The reversal of 72557361 is 16375527.

72557361 is a `hidden beast` number, since 7 + 25 + 573 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 64400625 + 8156736 = 8025^2 + 2856^2 .

It is not a de Polignac number, because 72557361 - 2² = 72557357 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72557369) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 4030956 + ... + 4030973.

It is an arithmetic number, because the mean of its divisors is an integer number (17467515).

Almost surely, 2^72557361 is an apocalyptic number.

It is an amenable number.

72557361 is a deficient number, since it is larger than the sum of its proper divisors (32247729).

72557361 is a wasteful number, since it uses less digits than its factorization.

72557361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8061935 (or 8061932 counting only the distinct ones).

The product of its digits is 44100, while the sum is 36.

The square root of 72557361 is about 8518.0608708790. The cubic root of 72557361 is about 417.0874857418.

The spelling of 72557361 in words is "seventy-two million, five hundred fifty-seven thousand, three hundred sixty-one".