20491572 has 12 divisors (see below), whose sum is σ = 47813696. Its totient is φ = 6830520.

The previous prime is 20491571. The next prime is 20491591. The reversal of 20491572 is 27519402.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20491571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 853804 + ... + 853827.

Almost surely, 2^20491572 is an apocalyptic number.

It is an amenable number.

20491572 is an abundant number, since it is smaller than the sum of its proper divisors (27322124).

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

20491572 is a wasteful number, since it uses less digits than its factorization.

20491572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1707638 (or 1707636 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 20491572 is about 4526.7617564877. The cubic root of 20491572 is about 273.6476726033.

The spelling of 20491572 in words is "twenty million, four hundred ninety-one thousand, five hundred seventy-two".