20972500 has 30 divisors (see below), whose sum is σ = 45868130. Its totient is φ = 8388000.

The previous prime is 20972473. The next prime is 20972513. The reversal of 20972500 is 527902.

It can be written as a sum of positive squares in 5 ways, for example, as 4309776 + 16662724 = 2076^2 + 4082^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1695 + ... + 6694.

Almost surely, 2^20972500 is an apocalyptic number.

20972500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20972500 is an abundant number, since it is smaller than the sum of its proper divisors (24895630).

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

20972500 is an equidigital number, since it uses as much as digits as its factorization.

20972500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8413 (or 8396 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 20972500 is about 4579.5742160162. The cubic root of 20972500 is about 275.7719358016.

The spelling of 20972500 in words is "twenty million, nine hundred seventy-two thousand, five hundred".