20917868 has 12 divisors (see below), whose sum is σ = 36638952. Its totient is φ = 10449600.

The previous prime is 20917861. The next prime is 20917873. The reversal of 20917868 is 86871902.

It is not an unprimeable number, because it can be changed into a prime (20917861) 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, 6068 + ... + 8868.

It is an arithmetic number, because the mean of its divisors is an integer number (3053246).

Almost surely, 2^20917868 is an apocalyptic number.

It is an amenable number.

20917868 is a deficient number, since it is larger than the sum of its proper divisors (15721084).

20917868 is a wasteful number, since it uses less digits than its factorization.

20917868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4672 (or 4670 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 20917868 is about 4573.6055798462. The cubic root of 20917868 is about 275.5322715854.

The spelling of 20917868 in words is "twenty million, nine hundred seventeen thousand, eight hundred sixty-eight".