72531561 has 8 divisors (see below), whose sum is σ = 97358400. Its totient is φ = 48029552.

The previous prime is 72531553. The next prime is 72531593. The reversal of 72531561 is 16513527.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72531561 - 2³ = 72531553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72531521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80685 + ... + 81578.

It is an arithmetic number, because the mean of its divisors is an integer number (12169800).

Almost surely, 2^72531561 is an apocalyptic number.

It is an amenable number.

72531561 is a deficient number, since it is larger than the sum of its proper divisors (24826839).

72531561 is a wasteful number, since it uses less digits than its factorization.

72531561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162415.

The product of its digits is 6300, while the sum is 30.

The square root of 72531561 is about 8516.5463070425. The cubic root of 72531561 is about 417.0380437891.

The spelling of 72531561 in words is "seventy-two million, five hundred thirty-one thousand, five hundred sixty-one".