21982128 has 40 divisors (see below), whose sum is σ = 64900608. Its totient is φ = 6280512.

The previous prime is 21982117. The next prime is 21982133. The reversal of 21982128 is 82128912.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32376 + ... + 33047.

Almost surely, 2^21982128 is an apocalyptic number.

21982128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21982128 is an abundant number, since it is smaller than the sum of its proper divisors (42918480).

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

21982128 is a wasteful number, since it uses less digits than its factorization.

21982128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65441 (or 65435 counting only the distinct ones).

The product of its digits is 4608, while the sum is 33.

The square root of 21982128 is about 4688.5102111438. The cubic root of 21982128 is about 280.1280366813.

The spelling of 21982128 in words is "twenty-one million, nine hundred eighty-two thousand, one hundred twenty-eight".