20621868 has 12 divisors (see below), whose sum is σ = 48117720. Its totient is φ = 6873952.

The previous prime is 20621827. The next prime is 20621891. The reversal of 20621868 is 86812602.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×20621868² = 850522879618848, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 859233 + ... + 859256.

It is an arithmetic number, because the mean of its divisors is an integer number (4009810).

Almost surely, 2^20621868 is an apocalyptic number.

It is an amenable number.

20621868 is an abundant number, since it is smaller than the sum of its proper divisors (27495852).

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

20621868 is a wasteful number, since it uses less digits than its factorization.

20621868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1718496 (or 1718494 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 20621868 is about 4541.1306962033. The cubic root of 20621868 is about 274.2264453721.

The spelling of 20621868 in words is "twenty million, six hundred twenty-one thousand, eight hundred sixty-eight".