21005452012 has 24 divisors (see below), whose sum is σ = 37866906000. Its totient is φ = 10189615296.

The previous prime is 21005451997. The next prime is 21005452043. The reversal of 21005452012 is 21025450012.

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, 384187 + ... + 435442.

It is an arithmetic number, because the mean of its divisors is an integer number (1577787750).

Almost surely, 2^21005452012 is an apocalyptic number.

It is an amenable number.

21005452012 is a deficient number, since it is larger than the sum of its proper divisors (16861453988).

21005452012 is a wasteful number, since it uses less digits than its factorization.

21005452012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819825 (or 819823 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

The spelling of 21005452012 in words is "twenty-one billion, five million, four hundred fifty-two thousand, twelve".