21620808 has 48 divisors (see below), whose sum is σ = 63882000. Its totient is φ = 6551520.

The previous prime is 21620801. The next prime is 21620827. The reversal of 21620808 is 80802612.

It is not an unprimeable number, because it can be changed into a prime (21620801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12858 + ... + 14441.

It is an arithmetic number, because the mean of its divisors is an integer number (1330875).

Almost surely, 2^21620808 is an apocalyptic number.

It is an amenable number.

21620808 is an abundant number, since it is smaller than the sum of its proper divisors (42261192).

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

21620808 is a wasteful number, since it uses less digits than its factorization.

21620808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27322 (or 27315 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21620808 is about 4649.8180609568. The cubic root of 21620808 is about 278.5847292607.

The spelling of 21620808 in words is "twenty-one million, six hundred twenty thousand, eight hundred eight".