21871912 has 16 divisors (see below), whose sum is σ = 41067360. Its totient is φ = 10920624.

The previous prime is 21871903. The next prime is 21871931. The reversal of 21871912 is 21917812.

It is an unprimeable number.

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, 6133 + ... + 9019.

It is an arithmetic number, because the mean of its divisors is an integer number (2566710).

Almost surely, 2^21871912 is an apocalyptic number.

It is an amenable number.

21871912 is a deficient number, since it is larger than the sum of its proper divisors (19195448).

21871912 is a wasteful number, since it uses less digits than its factorization.

21871912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3840 (or 3836 counting only the distinct ones).

The product of its digits is 2016, while the sum is 31.

The square root of 21871912 is about 4676.7416007301. The cubic root of 21871912 is about 279.6590748574.

The spelling of 21871912 in words is "twenty-one million, eight hundred seventy-one thousand, nine hundred twelve".