18438140872 has 16 divisors (see below), whose sum is σ = 34580676060. Its totient is φ = 9216627264.

The previous prime is 18438140837. The next prime is 18438140977. The reversal of 18438140872 is 27804183481.

It can be written as a sum of positive squares in 2 ways, for example, as 18378140356 + 60000516 = 135566^2 + 7746^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273123 + ... + 333874.

Almost surely, 2^18438140872 is an apocalyptic number.

It is an amenable number.

18438140872 is a deficient number, since it is larger than the sum of its proper divisors (16142535188).

18438140872 is a wasteful number, since it uses less digits than its factorization.

18438140872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610800 (or 610796 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 46.

The spelling of 18438140872 in words is "eighteen billion, four hundred thirty-eight million, one hundred forty thousand, eight hundred seventy-two".