21246864 has 40 divisors (see below), whose sum is σ = 57779040. Its totient is φ = 6709248.

The previous prime is 21246857. The next prime is 21246893. The reversal of 21246864 is 46864212.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10737 + ... + 12560.

It is an arithmetic number, because the mean of its divisors is an integer number (1444476).

Almost surely, 2^21246864 is an apocalyptic number.

21246864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21246864 is an abundant number, since it is smaller than the sum of its proper divisors (36532176).

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

21246864 is a wasteful number, since it uses less digits than its factorization.

21246864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23327 (or 23321 counting only the distinct ones).

The product of its digits is 18432, while the sum is 33.

The square root of 21246864 is about 4609.4320691382. The cubic root of 21246864 is about 276.9692867805.

The spelling of 21246864 in words is "twenty-one million, two hundred forty-six thousand, eight hundred sixty-four".