72715581 has 24 divisors (see below), whose sum is σ = 110859840. Its totient is φ = 45836736.

The previous prime is 72715571. The next prime is 72715589. The reversal of 72715581 is 18551727.

72715581 is a `hidden beast` number, since 7 + 2 + 71 + 5 + 581 = 666.

It is not a de Polignac number, because 72715581 - 2⁵ = 72715549 is a prime.

It is a super-2 number, since 2×72715581² = 10575111440335122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72715589) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16450 + ... + 20396.

It is an arithmetic number, because the mean of its divisors is an integer number (4619160).

Almost surely, 2^72715581 is an apocalyptic number.

It is an amenable number.

72715581 is a deficient number, since it is larger than the sum of its proper divisors (38144259).

72715581 is a wasteful number, since it uses less digits than its factorization.

72715581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4065 (or 4062 counting only the distinct ones).

The product of its digits is 19600, while the sum is 36.

The square root of 72715581 is about 8527.3431383990. The cubic root of 72715581 is about 417.3904353512.

The spelling of 72715581 in words is "seventy-two million, seven hundred fifteen thousand, five hundred eighty-one".