21286884 has 12 divisors (see below), whose sum is σ = 49669424. Its totient is φ = 7095624.

The previous prime is 21286871. The next prime is 21286919. The reversal of 21286884 is 48868212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

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 3 ways as a sum of consecutive naturals, for example, 886942 + ... + 886965.

Almost surely, 2^21286884 is an apocalyptic number.

It is an amenable number.

21286884 is an abundant number, since it is smaller than the sum of its proper divisors (28382540).

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

21286884 is a wasteful number, since it uses less digits than its factorization.

21286884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1773914 (or 1773912 counting only the distinct ones).

The product of its digits is 49152, while the sum is 39.

The square root of 21286884 is about 4613.7711256628. The cubic root of 21286884 is about 277.1430749180.

The spelling of 21286884 in words is "twenty-one million, two hundred eighty-six thousand, eight hundred eighty-four".