21985108 has 6 divisors (see below), whose sum is σ = 38473946. Its totient is φ = 10992552.

The previous prime is 21985091. The next prime is 21985127. The reversal of 21985108 is 80158912.

It can be written as a sum of positive squares in only one way, i.e., 19963024 + 2022084 = 4468^2 + 1422^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2748135 + ... + 2748142.

Almost surely, 2^21985108 is an apocalyptic number.

It is an amenable number.

21985108 is a deficient number, since it is larger than the sum of its proper divisors (16488838).

21985108 is a wasteful number, since it uses less digits than its factorization.

21985108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5496281 (or 5496279 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 21985108 is about 4688.8279985515. The cubic root of 21985108 is about 280.1406945980.

The spelling of 21985108 in words is "twenty-one million, nine hundred eighty-five thousand, one hundred eight".