18718031890 has 16 divisors (see below), whose sum is σ = 33938390232. Its totient is φ = 7432561024.

The previous prime is 18718031851. The next prime is 18718031903. The reversal of 18718031890 is 9813081781.

It can be written as a sum of positive squares in 4 ways, for example, as 18645083209 + 72948681 = 136547^2 + 8541^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18718031890.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6830029 + ... + 6832768.

Almost surely, 2^18718031890 is an apocalyptic number.

18718031890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18718031890 is a deficient number, since it is larger than the sum of its proper divisors (15220358342).

18718031890 is a wasteful number, since it uses less digits than its factorization.

18718031890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13662941.

The product of its (nonzero) digits is 96768, while the sum is 46.

The spelling of 18718031890 in words is "eighteen billion, seven hundred eighteen million, thirty-one thousand, eight hundred ninety".