172256813 has 16 divisors (see below), whose sum is σ = 179046720. Its totient is φ = 165648000.

The previous prime is 172256809. The next prime is 172256827. The reversal of 172256813 is 318652271.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 172256813 - 2² = 172256809 is a prime.

It is a super-3 number, since 3×172256813³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172256803) 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 15 ways as a sum of consecutive naturals, for example, 816278 + ... + 816488.

It is an arithmetic number, because the mean of its divisors is an integer number (11190420).

Almost surely, 2^172256813 is an apocalyptic number.

It is an amenable number.

172256813 is a deficient number, since it is larger than the sum of its proper divisors (6789907).

172256813 is a wasteful number, since it uses less digits than its factorization.

172256813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508.

The product of its digits is 20160, while the sum is 35.

The square root of 172256813 is about 13124.6643004688. The cubic root of 172256813 is about 556.4064245845.

The spelling of 172256813 in words is "one hundred seventy-two million, two hundred fifty-six thousand, eight hundred thirteen".