21046721859 has 64 divisors (see below), whose sum is σ = 32133818880. Its totient is φ = 13610488320.

The previous prime is 21046721809. The next prime is 21046721863. The reversal of 21046721859 is 95812764012.

21046721859 is a `hidden beast` number, since 2 + 1 + 0 + 467 + 2 + 185 + 9 = 666.

It is not a de Polignac number, because 21046721859 - 2¹⁵ = 21046689091 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21046721809) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 40396519 + ... + 40397039.

It is an arithmetic number, because the mean of its divisors is an integer number (502090920).

Almost surely, 2^21046721859 is an apocalyptic number.

21046721859 is a deficient number, since it is larger than the sum of its proper divisors (11087097021).

21046721859 is a wasteful number, since it uses less digits than its factorization.

21046721859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897 (or 891 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 21046721859 in words is "twenty-one billion, forty-six million, seven hundred twenty-one thousand, eight hundred fifty-nine".