172288638 has 24 divisors (see below), whose sum is σ = 385334976. Its totient is φ = 55576800.

The previous prime is 172288577. The next prime is 172288663. The reversal of 172288638 is 836882271.

172288638 is a `hidden beast` number, since 1 + 7 + 2 + 2 + 8 + 8 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 172288593 and 172288602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 153823 + ... + 154938.

It is an arithmetic number, because the mean of its divisors is an integer number (16055624).

Almost surely, 2^172288638 is an apocalyptic number.

172288638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

172288638 is an abundant number, since it is smaller than the sum of its proper divisors (213046338).

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

172288638 is a wasteful number, since it uses less digits than its factorization.

172288638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308800 (or 308797 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 172288638 is about 13125.8766564371. The cubic root of 172288638 is about 556.4406884330.

The spelling of 172288638 in words is "one hundred seventy-two million, two hundred eighty-eight thousand, six hundred thirty-eight".