21885756 has 12 divisors (see below), whose sum is σ = 51066792. Its totient is φ = 7295248.

The previous prime is 21885737. The next prime is 21885757. The reversal of 21885756 is 65758812.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21885757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 911895 + ... + 911918.

It is an arithmetic number, because the mean of its divisors is an integer number (4255566).

Almost surely, 2^21885756 is an apocalyptic number.

It is an amenable number.

21885756 is an abundant number, since it is smaller than the sum of its proper divisors (29181036).

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

21885756 is a wasteful number, since it uses less digits than its factorization.

21885756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823820 (or 1823818 counting only the distinct ones).

The product of its digits is 134400, while the sum is 42.

The square root of 21885756 is about 4678.2214569214. The cubic root of 21885756 is about 279.7180665552.

The spelling of 21885756 in words is "twenty-one million, eight hundred eighty-five thousand, seven hundred fifty-six".