20864025 has 72 divisors (see below), whose sum is σ = 46038720. Its totient is φ = 8795520.

The previous prime is 20864009. The next prime is 20864047. The reversal of 20864025 is 52046802.

It is not a de Polignac number, because 20864025 - 2⁴ = 20864009 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20864025.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 19966 + ... + 20984.

Almost surely, 2^20864025 is an apocalyptic number.

20864025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20864025 is an abundant number, since it is smaller than the sum of its proper divisors (25174695).

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

20864025 is a wasteful number, since it uses less digits than its factorization.

20864025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 20864025 is about 4567.7155121570. The cubic root of 20864025 is about 275.2956599754.

The spelling of 20864025 in words is "twenty million, eight hundred sixty-four thousand, twenty-five".