20868520 has 32 divisors (see below), whose sum is σ = 49717800. Its totient is φ = 7856128.

The previous prime is 20868509. The next prime is 20868539. The reversal of 20868520 is 2586802.

It can be written as a sum of positive squares in 4 ways, for example, as 20848356 + 20164 = 4566^2 + 142^2 .

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, 14665 + ... + 16024.

Almost surely, 2^20868520 is an apocalyptic number.

20868520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20868520 is an abundant number, since it is smaller than the sum of its proper divisors (28849280).

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

20868520 is a wasteful number, since it uses less digits than its factorization.

20868520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30717 (or 30713 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 20868520 is about 4568.2075259340. The cubic root of 20868520 is about 275.3154286943.

The spelling of 20868520 in words is "twenty million, eight hundred sixty-eight thousand, five hundred twenty".