20564872 has 8 divisors (see below), whose sum is σ = 38559150. Its totient is φ = 10282432.

The previous prime is 20564867. The next prime is 20564891. The reversal of 20564872 is 27846502.

It can be written as a sum of positive squares in only one way, i.e., 11600836 + 8964036 = 3406^2 + 2994^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1285297 + ... + 1285312.

Almost surely, 2^20564872 is an apocalyptic number.

It is an amenable number.

20564872 is a deficient number, since it is larger than the sum of its proper divisors (17994278).

20564872 is a wasteful number, since it uses less digits than its factorization.

20564872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2570615 (or 2570611 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 20564872 is about 4534.8508244484. The cubic root of 20564872 is about 273.9735708964.

The spelling of 20564872 in words is "twenty million, five hundred sixty-four thousand, eight hundred seventy-two".