21486756 has 24 divisors (see below), whose sum is σ = 51302944. Its totient is φ = 6995520.

The previous prime is 21486737. The next prime is 21486779. The reversal of 21486756 is 65768412.

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 7 ways as a sum of consecutive naturals, for example, 20305 + ... + 21336.

Almost surely, 2^21486756 is an apocalyptic number.

It is an amenable number.

21486756 is an abundant number, since it is smaller than the sum of its proper divisors (29816188).

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

21486756 is a wasteful number, since it uses less digits than its factorization.

21486756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41691 (or 41689 counting only the distinct ones).

The product of its digits is 80640, while the sum is 39.

The square root of 21486756 is about 4635.3808904986. The cubic root of 21486756 is about 278.0077806079.

The spelling of 21486756 in words is "twenty-one million, four hundred eighty-six thousand, seven hundred fifty-six".