20864878 has 16 divisors (see below), whose sum is σ = 32065920. Its totient is φ = 10179000.

The previous prime is 20864863. The next prime is 20864923. The reversal of 20864878 is 87846802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17233 + ... + 18403.

It is an arithmetic number, because the mean of its divisors is an integer number (2004120).

Almost surely, 2^20864878 is an apocalyptic number.

20864878 is a deficient number, since it is larger than the sum of its proper divisors (11201042).

20864878 is a wasteful number, since it uses less digits than its factorization.

20864878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1383.

The product of its (nonzero) digits is 172032, while the sum is 43.

The square root of 20864878 is about 4567.8088839180. The cubic root of 20864878 is about 275.2994116325.

The spelling of 20864878 in words is "twenty million, eight hundred sixty-four thousand, eight hundred seventy-eight".