172381856009 has 16 divisors (see below), whose sum is σ = 199159871040. Its totient is φ = 147459164160.

The previous prime is 172381855979. The next prime is 172381856021. The reversal of 172381856009 is 900658183271.

It is a de Polignac number, because none of the positive numbers 2^k-172381856009 is a prime.

It is a super-2 number, since 2×172381856009² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (172381856099) 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, 743897 + ... + 947705.

It is an arithmetic number, because the mean of its divisors is an integer number (12447491940).

Almost surely, 2^172381856009 is an apocalyptic number.

It is an amenable number.

172381856009 is a deficient number, since it is larger than the sum of its proper divisors (26778015031).

172381856009 is a wasteful number, since it uses less digits than its factorization.

172381856009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208360.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 172381856009 in words is "one hundred seventy-two billion, three hundred eighty-one million, eight hundred fifty-six thousand, nine".