18039278018 has 4 divisors (see below), whose sum is σ = 27058917030. Its totient is φ = 9019639008.

The previous prime is 18039277979. The next prime is 18039278027. The reversal of 18039278018 is 81087293081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81087293081 = 337 ⋅240615113.

It can be written as a sum of positive squares in only one way, i.e., 15315795049 + 2723482969 = 123757^2 + 52187^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4509819503 + ... + 4509819506.

Almost surely, 2^18039278018 is an apocalyptic number.

18039278018 is a deficient number, since it is larger than the sum of its proper divisors (9019639012).

18039278018 is an equidigital number, since it uses as much as digits as its factorization.

18039278018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9019639011.

The product of its (nonzero) digits is 193536, while the sum is 47.

The spelling of 18039278018 in words is "eighteen billion, thirty-nine million, two hundred seventy-eight thousand, eighteen".