72697531 has 4 divisors (see below), whose sum is σ = 73066752. Its totient is φ = 72328312.

The previous prime is 72697529. The next prime is 72697571. The reversal of 72697531 is 13579627.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72697531 - 2¹ = 72697529 is a prime.

It is a super-2 number, since 2×72697531² = 10569862026991922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72697571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 184315 + ... + 184708.

It is an arithmetic number, because the mean of its divisors is an integer number (18266688).

Almost surely, 2^72697531 is an apocalyptic number.

72697531 is a deficient number, since it is larger than the sum of its proper divisors (369221).

72697531 is a wasteful number, since it uses less digits than its factorization.

72697531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369220.

The product of its digits is 79380, while the sum is 40.

The square root of 72697531 is about 8526.2847125814. The cubic root of 72697531 is about 417.3558965783.

The spelling of 72697531 in words is "seventy-two million, six hundred ninety-seven thousand, five hundred thirty-one".