21982120 has 16 divisors (see below), whose sum is σ = 49459860. Its totient is φ = 8792832.

The previous prime is 21982117. The next prime is 21982133. The reversal of 21982120 is 2128912.

It can be written as a sum of positive squares in 2 ways, for example, as 21696964 + 285156 = 4658^2 + 534^2 .

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, 274737 + ... + 274816.

Almost surely, 2^21982120 is an apocalyptic number.

21982120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21982120 is an abundant number, since it is smaller than the sum of its proper divisors (27477740).

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

21982120 is a wasteful number, since it uses less digits than its factorization.

21982120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549564 (or 549560 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 21982120 is about 4688.5093579943. The cubic root of 21982120 is about 280.1280026988.

The spelling of 21982120 in words is "twenty-one million, nine hundred eighty-two thousand, one hundred twenty".