72940645521 has 24 divisors (see below), whose sum is σ = 106417920960. Its totient is φ = 48138554016.

The previous prime is 72940645501. The next prime is 72940645537. The reversal of 72940645521 is 12554604927.

72940645521 is a `hidden beast` number, since 7 + 2 + 94 + 0 + 6 + 4 + 552 + 1 = 666.

It is not a de Polignac number, because 72940645521 - 2¹⁸ = 72940383377 is a prime.

It is a super-2 number, since 2×72940645521² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72940645501) 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, 3090915 + ... + 3114423.

It is an arithmetic number, because the mean of its divisors is an integer number (4434080040).

Almost surely, 2^72940645521 is an apocalyptic number.

It is an amenable number.

72940645521 is a deficient number, since it is larger than the sum of its proper divisors (33477275439).

72940645521 is a wasteful number, since it uses less digits than its factorization.

72940645521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26965 (or 26962 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 72940645521 in words is "seventy-two billion, nine hundred forty million, six hundred forty-five thousand, five hundred twenty-one".