20864818 has 48 divisors (see below), whose sum is σ = 37068696. Its totient is φ = 8743680.

The previous prime is 20864807. The next prime is 20864821. The reversal of 20864818 is 81846802.

It can be written as a sum of positive squares in 4 ways, for example, as 13373649 + 7491169 = 3657^2 + 2737^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 508878 + ... + 508918.

Almost surely, 2^20864818 is an apocalyptic number.

20864818 is a deficient number, since it is larger than the sum of its proper divisors (16203878).

20864818 is a wasteful number, since it uses less digits than its factorization.

20864818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 20864818 is about 4567.8023162129. The cubic root of 20864818 is about 275.2991477443.

The spelling of 20864818 in words is "twenty million, eight hundred sixty-four thousand, eight hundred eighteen".