21384868 has 12 divisors (see below), whose sum is σ = 37507932. Its totient is φ = 10668320.

The previous prime is 21384841. The next prime is 21384877. The reversal of 21384868 is 86848312.

It can be written as a sum of positive squares in 2 ways, for example, as 13307904 + 8076964 = 3648^2 + 2842^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21384868.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3955 + ... + 7642.

It is an arithmetic number, because the mean of its divisors is an integer number (3125661).

Almost surely, 2^21384868 is an apocalyptic number.

It is an amenable number.

21384868 is a deficient number, since it is larger than the sum of its proper divisors (16123064).

21384868 is a wasteful number, since it uses less digits than its factorization.

21384868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12062 (or 12060 counting only the distinct ones).

The product of its digits is 73728, while the sum is 40.

The square root of 21384868 is about 4624.3775797398. The cubic root of 21384868 is about 277.5676560411.

The spelling of 21384868 in words is "twenty-one million, three hundred eighty-four thousand, eight hundred sixty-eight".