20972288 has 72 divisors (see below), whose sum is σ = 45622080. Its totient is φ = 9584640.

The previous prime is 20972269. The next prime is 20972291. The reversal of 20972288 is 88227902.

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, 265433 + ... + 265511.

It is an arithmetic number, because the mean of its divisors is an integer number (633640).

Almost surely, 2^20972288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20972288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22811040).

20972288 is an abundant number, since it is smaller than the sum of its proper divisors (24649792).

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

20972288 is an equidigital number, since it uses as much as digits as its factorization.

20972288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 20972288 is about 4579.5510697010. The cubic root of 20972288 is about 275.7710065872.

The spelling of 20972288 in words is "twenty million, nine hundred seventy-two thousand, two hundred eighty-eight".