18318039538 has 4 divisors (see below), whose sum is σ = 27477059310. Its totient is φ = 9159019768.

The previous prime is 18318039533. The next prime is 18318039539. The reversal of 18318039538 is 83593081381.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11807647569 + 6510391969 = 108663^2 + 80687^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18318039491 and 18318039500.

It is not an unprimeable number, because it can be changed into a prime (18318039533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4579509883 + ... + 4579509886.

Almost surely, 2^18318039538 is an apocalyptic number.

18318039538 is a deficient number, since it is larger than the sum of its proper divisors (9159019772).

18318039538 is an equidigital number, since it uses as much as digits as its factorization.

18318039538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9159019771.

The product of its (nonzero) digits is 622080, while the sum is 49.

The spelling of 18318039538 in words is "eighteen billion, three hundred eighteen million, thirty-nine thousand, five hundred thirty-eight".