21976456 has 16 divisors (see below), whose sum is σ = 41504400. Its totient is φ = 10908624.

The previous prime is 21976441. The next prime is 21976463. The reversal of 21976456 is 65467912.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8770 + ... + 10993.

It is an arithmetic number, because the mean of its divisors is an integer number (2594025).

Almost surely, 2^21976456 is an apocalyptic number.

It is an amenable number.

21976456 is a deficient number, since it is larger than the sum of its proper divisors (19527944).

21976456 is a wasteful number, since it uses less digits than its factorization.

21976456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19908 (or 19904 counting only the distinct ones).

The product of its digits is 90720, while the sum is 40.

The square root of 21976456 is about 4687.9052891457. The cubic root of 21976456 is about 280.1039410023.

The spelling of 21976456 in words is "twenty-one million, nine hundred seventy-six thousand, four hundred fifty-six".