172218868 has 12 divisors (see below), whose sum is σ = 309528772. Its totient is φ = 83782080.

The previous prime is 172218863. The next prime is 172218929. The reversal of 172218868 is 868812271.

It can be written as a sum of positive squares in 2 ways, for example, as 139523344 + 32695524 = 11812^2 + 5718^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172218863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 581673 + ... + 581968.

Almost surely, 2^172218868 is an apocalyptic number.

It is an amenable number.

172218868 is a deficient number, since it is larger than the sum of its proper divisors (137309904).

172218868 is a wasteful number, since it uses less digits than its factorization.

172218868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1163682 (or 1163680 counting only the distinct ones).

The product of its digits is 86016, while the sum is 43.

The square root of 172218868 is about 13123.2186600696. The cubic root of 172218868 is about 556.3655662253.

The spelling of 172218868 in words is "one hundred seventy-two million, two hundred eighteen thousand, eight hundred sixty-eight".