21109912 has 32 divisors (see below), whose sum is σ = 43110000. Its totient is φ = 9652608.

The previous prime is 21109901. The next prime is 21109927. The reversal of 21109912 is 21990112.

It is a congruent number.

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, 2014 + ... + 6802.

Almost surely, 2^21109912 is an apocalyptic number.

It is an amenable number.

21109912 is an abundant number, since it is smaller than the sum of its proper divisors (22000088).

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

21109912 is a wasteful number, since it uses less digits than its factorization.

21109912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4843 (or 4839 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 21109912 is about 4594.5524265156. The cubic root of 21109912 is about 276.3729118697.

The spelling of 21109912 in words is "twenty-one million, one hundred nine thousand, nine hundred twelve".