21159918612 has 144 divisors (see below), whose sum is σ = 61675449472. Its totient is φ = 5991874560.

The previous prime is 21159918607. The next prime is 21159918667. The reversal of 21159918612 is 21681995112.

21159918612 is a `hidden beast` number, since 2 + 1 + 15 + 9 + 9 + 18 + 612 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16389687 + ... + 16390977.

Almost surely, 2^21159918612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21159918612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30837724736).

21159918612 is an abundant number, since it is smaller than the sum of its proper divisors (40515530860).

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

21159918612 is a wasteful number, since it uses less digits than its factorization.

21159918612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1838 (or 1833 counting only the distinct ones).

The product of its digits is 77760, while the sum is 45.

The spelling of 21159918612 in words is "twenty-one billion, one hundred fifty-nine million, nine hundred eighteen thousand, six hundred twelve".