72640686 has 16 divisors (see below), whose sum is σ = 152928000. Its totient is φ = 22939128.

The previous prime is 72640661. The next prime is 72640703. The reversal of 72640686 is 68604627.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 318486 + ... + 318713.

It is an arithmetic number, because the mean of its divisors is an integer number (9558000).

Almost surely, 2^72640686 is an apocalyptic number.

72640686 is an abundant number, since it is smaller than the sum of its proper divisors (80287314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72640686 is a wasteful number, since it uses less digits than its factorization.

72640686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637223.

The product of its (nonzero) digits is 96768, while the sum is 39.

The square root of 72640686 is about 8522.9505454391. The cubic root of 72640686 is about 417.2470859945.

The spelling of 72640686 in words is "seventy-two million, six hundred forty thousand, six hundred eighty-six".