21310956 has 36 divisors (see below), whose sum is σ = 54049632. Its totient is φ = 7079904.

The previous prime is 21310937. The next prime is 21310957. The reversal of 21310956 is 65901312.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310957) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 12406 + ... + 14018.

Almost surely, 2^21310956 is an apocalyptic number.

It is an amenable number.

21310956 is an abundant number, since it is smaller than the sum of its proper divisors (32738676).

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

21310956 is a wasteful number, since it uses less digits than its factorization.

21310956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1990 (or 1985 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 21310956 is about 4616.3791005506. The cubic root of 21310956 is about 277.2475034623.

The spelling of 21310956 in words is "twenty-one million, three hundred ten thousand, nine hundred fifty-six".