21103912 has 32 divisors (see below), whose sum is σ = 41176800. Its totient is φ = 10131264.

The previous prime is 21103897. The next prime is 21103933. The reversal of 21103912 is 21930112.

It is a self number, because there is not a number n which added to its sum of digits gives 21103912.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24139 + ... + 24997.

It is an arithmetic number, because the mean of its divisors is an integer number (1286775).

Almost surely, 2^21103912 is an apocalyptic number.

It is an amenable number.

21103912 is a deficient number, since it is larger than the sum of its proper divisors (20072888).

21103912 is a wasteful number, since it uses less digits than its factorization.

21103912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985 (or 981 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21103912 is about 4593.8994329437. The cubic root of 21103912 is about 276.3467252044.

The spelling of 21103912 in words is "twenty-one million, one hundred three thousand, nine hundred twelve".