20697864 has 32 divisors (see below), whose sum is σ = 56449440. Its totient is φ = 6272000.

The previous prime is 20697847. The next prime is 20697877. The reversal of 20697864 is 46879602.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38937 + ... + 39464.

It is an arithmetic number, because the mean of its divisors is an integer number (1764045).

Almost surely, 2^20697864 is an apocalyptic number.

20697864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20697864 is an abundant number, since it is smaller than the sum of its proper divisors (35751576).

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

20697864 is a wasteful number, since it uses less digits than its factorization.

20697864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78421 (or 78417 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 20697864 is about 4549.4905209265. The cubic root of 20697864 is about 274.5628934756.

The spelling of 20697864 in words is "twenty million, six hundred ninety-seven thousand, eight hundred sixty-four".