18391693018 has 8 divisors (see below), whose sum is σ = 27600455412. Its totient is φ = 9191541216.

The previous prime is 18391693007. The next prime is 18391693031. The reversal of 18391693018 is 81039619381.

It can be written as a sum of positive squares in 2 ways, for example, as 18251199409 + 140493609 = 135097^2 + 11853^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 2147305 + ... + 2155852.

Almost surely, 2^18391693018 is an apocalyptic number.

18391693018 is a deficient number, since it is larger than the sum of its proper divisors (9208762394).

18391693018 is a wasteful number, since it uses less digits than its factorization.

18391693018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4305296.

The product of its (nonzero) digits is 279936, while the sum is 49.

The spelling of 18391693018 in words is "eighteen billion, three hundred ninety-one million, six hundred ninety-three thousand, eighteen".