20865920 has 32 divisors (see below), whose sum is σ = 49884120. Its totient is φ = 8346112.

The previous prime is 20865863. The next prime is 20865931. The reversal of 20865920 is 2956802.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15662 + ... + 16941.

Almost surely, 2^20865920 is an apocalyptic number.

20865920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20865920 is an abundant number, since it is smaller than the sum of its proper divisors (29018200).

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

20865920 is an equidigital number, since it uses as much as digits as its factorization.

20865920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32622 (or 32610 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 20865920 is about 4567.9229415567. The cubic root of 20865920 is about 275.3039944089.

The spelling of 20865920 in words is "twenty million, eight hundred sixty-five thousand, nine hundred twenty".