20957564 has 6 divisors (see below), whose sum is σ = 36675744. Its totient is φ = 10478780.

The previous prime is 20957561. The next prime is 20957593. The reversal of 20957564 is 46575902.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20957561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2619692 + ... + 2619699.

It is an arithmetic number, because the mean of its divisors is an integer number (6112624).

Almost surely, 2^20957564 is an apocalyptic number.

It is an amenable number.

20957564 is a deficient number, since it is larger than the sum of its proper divisors (15718180).

20957564 is a wasteful number, since it uses less digits than its factorization.

20957564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5239395 (or 5239393 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 20957564 is about 4577.9432062882. The cubic root of 20957564 is about 275.7064546904.

The spelling of 20957564 in words is "twenty million, nine hundred fifty-seven thousand, five hundred sixty-four".