20390808 has 32 divisors (see below), whose sum is σ = 52623360. Its totient is φ = 6577440.

The previous prime is 20390767. The next prime is 20390827. The reversal of 20390808 is 80809302.

It is a congruent number.

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, 12960 + ... + 14447.

It is an arithmetic number, because the mean of its divisors is an integer number (1644480).

Almost surely, 2^20390808 is an apocalyptic number.

It is an amenable number.

20390808 is an abundant number, since it is smaller than the sum of its proper divisors (32232552).

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

20390808 is a wasteful number, since it uses less digits than its factorization.

20390808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27447 (or 27443 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 20390808 is about 4515.6182300987. The cubic root of 20390808 is about 273.1983959513.

The spelling of 20390808 in words is "twenty million, three hundred ninety thousand, eight hundred eight".