21175868 has 12 divisors (see below), whose sum is σ = 42351792. Its totient is φ = 9075360.

The previous prime is 21175849. The next prime is 21175907. The reversal of 21175868 is 86857112.

21175868 is an admirable number.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 378113 + ... + 378168.

It is an arithmetic number, because the mean of its divisors is an integer number (3529316).

Almost surely, 2^21175868 is an apocalyptic number.

21175868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21175868 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21175868 is a wasteful number, since it uses less digits than its factorization.

21175868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756292 (or 756290 counting only the distinct ones).

The product of its digits is 26880, while the sum is 38.

The square root of 21175868 is about 4601.7244593739. The cubic root of 21175868 is about 276.6604466271.

The spelling of 21175868 in words is "twenty-one million, one hundred seventy-five thousand, eight hundred sixty-eight".