72531657 has 24 divisors (see below), whose sum is σ = 114903360. Its totient is φ = 43723680.

The previous prime is 72531647. The next prime is 72531659. The reversal of 72531657 is 75613527.

72531657 is a `hidden beast` number, since 72 + 531 + 6 + 57 = 666.

It is not a de Polignac number, because 72531657 - 2⁶ = 72531593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72531659) 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, 17644 + ... + 21362.

It is an arithmetic number, because the mean of its divisors is an integer number (4787640).

Almost surely, 2^72531657 is an apocalyptic number.

It is an amenable number.

72531657 is a deficient number, since it is larger than the sum of its proper divisors (42371703).

72531657 is a wasteful number, since it uses less digits than its factorization.

72531657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3933 (or 3930 counting only the distinct ones).

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

The square root of 72531657 is about 8516.5519431282. The cubic root of 72531657 is about 417.0382277809.

The spelling of 72531657 in words is "seventy-two million, five hundred thirty-one thousand, six hundred fifty-seven".