21056886 has 12 divisors (see below), whose sum is σ = 45623292. Its totient is φ = 7018956.

The previous prime is 21056873. The next prime is 21056899. The reversal of 21056886 is 68865012.

It is a happy number.

21056886 is a `hidden beast` number, since 2 + 10 + 568 + 86 = 666.

It is an interprime number because it is at equal distance from previous prime (21056873) and next prime (21056899).

It is a self number, because there is not a number n which added to its sum of digits gives 21056886.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 584896 + ... + 584931.

It is an arithmetic number, because the mean of its divisors is an integer number (3801941).

Almost surely, 2^21056886 is an apocalyptic number.

21056886 is an abundant number, since it is smaller than the sum of its proper divisors (24566406).

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

21056886 is a wasteful number, since it uses less digits than its factorization.

21056886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1169835 (or 1169832 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 21056886 is about 4588.7782687770. The cubic root of 21056886 is about 276.1413107500.

The spelling of 21056886 in words is "twenty-one million, fifty-six thousand, eight hundred eighty-six".