20457664 has 28 divisors (see below), whose sum is σ = 42985944. Its totient is φ = 9626624.

The previous prime is 20457617. The next prime is 20457677. The reversal of 20457664 is 46675402.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8314 + ... + 10489.

Almost surely, 2^20457664 is an apocalyptic number.

It is an amenable number.

20457664 is an abundant number, since it is smaller than the sum of its proper divisors (22528280).

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

20457664 is a wasteful number, since it uses less digits than its factorization.

20457664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18832 (or 18822 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 34.

The square root of 20457664 is about 4523.0149236986. The cubic root of 20457664 is about 273.4966516863.

The spelling of 20457664 in words is "twenty million, four hundred fifty-seven thousand, six hundred sixty-four".