20920400 has 30 divisors (see below), whose sum is σ = 50262222. Its totient is φ = 8368000.

The previous prime is 20920391. The next prime is 20920411. The reversal of 20920400 is 402902.

It can be written as a sum of positive squares in 3 ways, for example, as 4631104 + 16289296 = 2152^2 + 4036^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25751 + ... + 26550.

Almost surely, 2^20920400 is an apocalyptic number.

20920400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20920400 is an abundant number, since it is smaller than the sum of its proper divisors (29341822).

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

20920400 is a wasteful number, since it uses less digits than its factorization.

20920400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52319 (or 52308 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 20920400 is about 4573.8823771496. The cubic root of 20920400 is about 275.5433883902.

The spelling of 20920400 in words is "twenty million, nine hundred twenty thousand, four hundred".