72688537 has 4 divisors (see below), whose sum is σ = 72728676. Its totient is φ = 72648400.

The previous prime is 72688523. The next prime is 72688543. The reversal of 72688537 is 73588627.

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

It can be written as a sum of positive squares in 2 ways, for example, as 19456921 + 53231616 = 4411^2 + 7296^2 .

It is a cyclic number.

It is not a de Polignac number, because 72688537 - 2⁷ = 72688409 is a prime.

It is a super-2 number, since 2×72688537² = 10567246822400738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72688507) 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, 17218 + ... + 21019.

It is an arithmetic number, because the mean of its divisors is an integer number (18182169).

Almost surely, 2^72688537 is an apocalyptic number.

It is an amenable number.

72688537 is a deficient number, since it is larger than the sum of its proper divisors (40139).

72688537 is a wasteful number, since it uses less digits than its factorization.

72688537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40138.

The product of its digits is 564480, while the sum is 46.

The square root of 72688537 is about 8525.7572684190. The cubic root of 72688537 is about 417.3386843764.

The spelling of 72688537 in words is "seventy-two million, six hundred eighty-eight thousand, five hundred thirty-seven".