20564057 has 4 divisors (see below), whose sum is σ = 20679120. Its totient is φ = 20448996.

The previous prime is 20564041. The next prime is 20564059. The reversal of 20564057 is 75046502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20564057 - 2⁴ = 20564041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20564059) 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, 57263 + ... + 57620.

It is an arithmetic number, because the mean of its divisors is an integer number (5169780).

Almost surely, 2^20564057 is an apocalyptic number.

It is an amenable number.

20564057 is a deficient number, since it is larger than the sum of its proper divisors (115063).

20564057 is a wasteful number, since it uses less digits than its factorization.

20564057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115062.

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 20564057 is about 4534.7609639318. The cubic root of 20564057 is about 273.9699515950.

The spelling of 20564057 in words is "twenty million, five hundred sixty-four thousand, fifty-seven".