21982872 has 32 divisors (see below), whose sum is σ = 55079280. Its totient is φ = 7311360.

The previous prime is 21982861. The next prime is 21982879. The reversal of 21982872 is 27828912.

It is a super-2 number, since 2×21982872² = 966493322736768, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21982872.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21982879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15472 + ... + 16832.

Almost surely, 2^21982872 is an apocalyptic number.

It is an amenable number.

21982872 is an abundant number, since it is smaller than the sum of its proper divisors (33096408).

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

21982872 is a wasteful number, since it uses less digits than its factorization.

21982872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2043 (or 2039 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The square root of 21982872 is about 4688.5895533732. The cubic root of 21982872 is about 280.1311970200.

The spelling of 21982872 in words is "twenty-one million, nine hundred eighty-two thousand, eight hundred seventy-two".