18021765008 has 40 divisors (see below), whose sum is σ = 39815061048. Its totient is φ = 7828457472.

The previous prime is 18021764951. The next prime is 18021765037. The reversal of 18021765008 is 80056712081.

It can be written as a sum of positive squares in 4 ways, for example, as 1263944704 + 16757820304 = 35552^2 + 129452^2 .

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, 2544791 + ... + 2551862.

Almost surely, 2^18021765008 is an apocalyptic number.

It is an amenable number.

18021765008 is an abundant number, since it is smaller than the sum of its proper divisors (21793296040).

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

18021765008 is a wasteful number, since it uses less digits than its factorization.

18021765008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5096691 (or 5096685 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 38.

The spelling of 18021765008 in words is "eighteen billion, twenty-one million, seven hundred sixty-five thousand, eight".