21105605612 has 48 divisors (see below), whose sum is σ = 47850781440. Its totient is φ = 7910021952.

The previous prime is 21105605579. The next prime is 21105605627. The reversal of 21105605612 is 21650650112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1518938 + ... + 1532769.

It is an arithmetic number, because the mean of its divisors is an integer number (996891280).

Almost surely, 2^21105605612 is an apocalyptic number.

It is an amenable number.

21105605612 is an abundant number, since it is smaller than the sum of its proper divisors (26745175828).

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

21105605612 is a wasteful number, since it uses less digits than its factorization.

21105605612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3051750 (or 3051748 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

The spelling of 21105605612 in words is "twenty-one billion, one hundred five million, six hundred five thousand, six hundred twelve".