72910521817 has 16 divisors (see below), whose sum is σ = 85536057600. Its totient is φ = 62120464224.

The previous prime is 72910521811. The next prime is 72910521823. The reversal of 72910521817 is 71812501927.

It is an interprime number because it is at equal distance from previous prime (72910521811) and next prime (72910521823).

It is not a de Polignac number, because 72910521817 - 2³ = 72910521809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72910521811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 579148 + ... + 693709.

It is an arithmetic number, because the mean of its divisors is an integer number (5346003600).

Almost surely, 2^72910521817 is an apocalyptic number.

It is an amenable number.

72910521817 is a deficient number, since it is larger than the sum of its proper divisors (12625535783).

72910521817 is a wasteful number, since it uses less digits than its factorization.

72910521817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273045 (or 1273031 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 43.

The spelling of 72910521817 in words is "seventy-two billion, nine hundred ten million, five hundred twenty-one thousand, eight hundred seventeen".