21858168 has 32 divisors (see below), whose sum is σ = 55002960. Its totient is φ = 7238400.

The previous prime is 21858163. The next prime is 21858197. The reversal of 21858168 is 86185812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21858163) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 868 + ... + 6668.

Almost surely, 2^21858168 is an apocalyptic number.

It is an amenable number.

21858168 is an abundant number, since it is smaller than the sum of its proper divisors (33144792).

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

21858168 is a wasteful number, since it uses less digits than its factorization.

21858168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5967 (or 5963 counting only the distinct ones).

The product of its digits is 30720, while the sum is 39.

The square root of 21858168 is about 4675.2719706986. The cubic root of 21858168 is about 279.6004846482.

The spelling of 21858168 in words is "twenty-one million, eight hundred fifty-eight thousand, one hundred sixty-eight".