72720657 has 24 divisors (see below), whose sum is σ = 111290400. Its totient is φ = 45629568.

The previous prime is 72720631. The next prime is 72720667. The reversal of 72720657 is 75602727.

It is not a de Polignac number, because 72720657 - 2¹¹ = 72718609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72720607) 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, 26569 + ... + 29177.

It is an arithmetic number, because the mean of its divisors is an integer number (4637100).

Almost surely, 2^72720657 is an apocalyptic number.

It is an amenable number.

72720657 is a deficient number, since it is larger than the sum of its proper divisors (38569743).

72720657 is a wasteful number, since it uses less digits than its factorization.

72720657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2797 (or 2794 counting only the distinct ones).

The product of its (nonzero) digits is 41160, while the sum is 36.

The square root of 72720657 is about 8527.6407640097. The cubic root of 72720657 is about 417.4001472750.

The spelling of 72720657 in words is "seventy-two million, seven hundred twenty thousand, six hundred fifty-seven".