21982656 has 28 divisors (see below), whose sum is σ = 58162952. Its totient is φ = 7327488.

The previous prime is 21982643. The next prime is 21982657. The reversal of 21982656 is 65628912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21982657) 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 3 ways as a sum of consecutive naturals, for example, 57055 + ... + 57438.

Almost surely, 2^21982656 is an apocalyptic number.

It is an amenable number.

21982656 is an abundant number, since it is smaller than the sum of its proper divisors (36180296).

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

21982656 is a wasteful number, since it uses less digits than its factorization.

21982656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114508 (or 114498 counting only the distinct ones).

The product of its digits is 51840, while the sum is 39.

The square root of 21982656 is about 4688.5665186707. The cubic root of 21982656 is about 280.1302795097.

The spelling of 21982656 in words is "twenty-one million, nine hundred eighty-two thousand, six hundred fifty-six".