172520817 has 36 divisors (see below), whose sum is σ = 282494736. Its totient is φ = 93366000.

The previous prime is 172520801. The next prime is 172520819. The reversal of 172520817 is 718025271.

It is not a de Polignac number, because 172520817 - 2⁴ = 172520801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (172520819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 51442 + ... + 54692.

It is an arithmetic number, because the mean of its divisors is an integer number (7847076).

Almost surely, 2^172520817 is an apocalyptic number.

It is an amenable number.

172520817 is a deficient number, since it is larger than the sum of its proper divisors (109973919).

172520817 is a wasteful number, since it uses less digits than its factorization.

172520817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3306 (or 3280 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 33.

The square root of 172520817 is about 13134.7180023021. The cubic root of 172520817 is about 556.6905324408.

The spelling of 172520817 in words is "one hundred seventy-two million, five hundred twenty thousand, eight hundred seventeen".