21710956 has 12 divisors (see below), whose sum is σ = 38192392. Its totient is φ = 10798848.

The previous prime is 21710951. The next prime is 21710957. The reversal of 21710956 is 65901712.

It is a super-2 number, since 2×21710956² = 942731220867872, which contains 22 as substring.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21710951) by changing a digit.

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, 13290 + ... + 14833.

Almost surely, 2^21710956 is an apocalyptic number.

It is an amenable number.

21710956 is a deficient number, since it is larger than the sum of its proper divisors (16481436).

21710956 is a wasteful number, since it uses less digits than its factorization.

21710956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28320 (or 28318 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 21710956 is about 4659.5016900952. The cubic root of 21710956 is about 278.9713788979.

The spelling of 21710956 in words is "twenty-one million, seven hundred ten thousand, nine hundred fifty-six".