172121994 has 24 divisors (see below), whose sum is σ = 406834272. Its totient is φ = 52158120.

The previous prime is 172121987. The next prime is 172122001. The reversal of 172121994 is 499121271.

It is an interprime number because it is at equal distance from previous prime (172121987) and next prime (172122001).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 434454 + ... + 434849.

It is an arithmetic number, because the mean of its divisors is an integer number (16951428).

Almost surely, 2^172121994 is an apocalyptic number.

172121994 is an abundant number, since it is smaller than the sum of its proper divisors (234712278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

172121994 is a wasteful number, since it uses less digits than its factorization.

172121994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869322 (or 869319 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 172121994 is about 13119.5272018469. The cubic root of 172121994 is about 556.2612271605.

The spelling of 172121994 in words is "one hundred seventy-two million, one hundred twenty-one thousand, nine hundred ninety-four".