172855881 has 36 divisors (see below), whose sum is σ = 290617236. Its totient is φ = 98588160.

The previous prime is 172855853. The next prime is 172855909. The reversal of 172855881 is 188558271.

172855881 is a `hidden beast` number, since 17 + 2 + 8 + 558 + 81 = 666.

It is an interprime number because it is at equal distance from previous prime (172855853) and next prime (172855909).

It can be written as a sum of positive squares in 2 ways, for example, as 151511481 + 21344400 = 12309^2 + 4620^2 .

It is not a de Polignac number, because 172855881 - 2⁵ = 172855849 is a prime.

It is a super-2 number, since 2×172855881² = 59758311192572322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (172855381) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13845 + ... + 23181.

It is an arithmetic number, because the mean of its divisors is an integer number (8072701).

Almost surely, 2^172855881 is an apocalyptic number.

172855881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

172855881 is a deficient number, since it is larger than the sum of its proper divisors (117761355).

172855881 is a wasteful number, since it uses less digits than its factorization.

172855881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9382 (or 9368 counting only the distinct ones).

The product of its digits is 179200, while the sum is 45.

The square root of 172855881 is about 13147.4667141621. The cubic root of 172855881 is about 557.0506944481.

The spelling of 172855881 in words is "one hundred seventy-two million, eight hundred fifty-five thousand, eight hundred eighty-one".