20812990 has 32 divisors (see below), whose sum is σ = 41057280. Its totient is φ = 7533600.

The previous prime is 20812973. The next prime is 20812993. The reversal of 20812990 is 9921802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20812993) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47191 + ... + 47629.

It is an arithmetic number, because the mean of its divisors is an integer number (1283040).

Almost surely, 2^20812990 is an apocalyptic number.

20812990 is a deficient number, since it is larger than the sum of its proper divisors (20244290).

20812990 is a wasteful number, since it uses less digits than its factorization.

20812990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20812990 is about 4562.1256010768. The cubic root of 20812990 is about 275.0710119644.

The spelling of 20812990 in words is "twenty million, eight hundred twelve thousand, nine hundred ninety".