72817560517 has 16 divisors (see below), whose sum is σ = 79511943280. Its totient is φ = 66279762432.

The previous prime is 72817560511. The next prime is 72817560533. The reversal of 72817560517 is 71506571827.

It can be written as a sum of positive squares in 8 ways, for example, as 2418082276 + 70399478241 = 49174^2 + 265329^2 .

It is not a de Polignac number, because 72817560517 - 2³ = 72817560509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72817560511) 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, 6361123 + ... + 6372559.

It is an arithmetic number, because the mean of its divisors is an integer number (4969496455).

Almost surely, 2^72817560517 is an apocalyptic number.

It is an amenable number.

72817560517 is a deficient number, since it is larger than the sum of its proper divisors (6694382763).

72817560517 is a wasteful number, since it uses less digits than its factorization.

72817560517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18232.

The product of its (nonzero) digits is 823200, while the sum is 49.

The spelling of 72817560517 in words is "seventy-two billion, eight hundred seventeen million, five hundred sixty thousand, five hundred seventeen".