20431872 has 88 divisors (see below), whose sum is σ = 60591200. Its totient is φ = 6801408.

The previous prime is 20431867. The next prime is 20431891. The reversal of 20431872 is 27813402.

It is a super-2 number, since 2×20431872² = 834922786848768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 27279 + ... + 28017.

Almost surely, 2^20431872 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 20431872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30295600).

20431872 is an abundant number, since it is smaller than the sum of its proper divisors (40159328).

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

20431872 is an equidigital number, since it uses as much as digits as its factorization.

20431872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768 (or 744 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 20431872 is about 4520.1628289255. The cubic root of 20431872 is about 273.3816663818.

The spelling of 20431872 in words is "twenty million, four hundred thirty-one thousand, eight hundred seventy-two".