18318031506 has 12 divisors (see below), whose sum is σ = 39689068302. Its totient is φ = 6106010496.

The previous prime is 18318031493. The next prime is 18318031507. The reversal of 18318031506 is 60513081381.

18318031506 is a `hidden beast` number, since 18 + 31 + 80 + 31 + 506 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18140049225 + 177982281 = 134685^2 + 13341^2 .

It is not an unprimeable number, because it can be changed into a prime (18318031507) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 508834191 + ... + 508834226.

Almost surely, 2^18318031506 is an apocalyptic number.

18318031506 is an abundant number, since it is smaller than the sum of its proper divisors (21371036796).

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

18318031506 is a wasteful number, since it uses less digits than its factorization.

18318031506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017668425 (or 1017668422 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 18318031506 in words is "eighteen billion, three hundred eighteen million, thirty-one thousand, five hundred six".