19819800018 has 24 divisors (see below), whose sum is σ = 42954992028. Its totient is φ = 6604739712.

The previous prime is 19819799999. The next prime is 19819800061. The reversal of 19819800018 is 81000891891.

It can be written as a sum of positive squares in 2 ways, for example, as 19501284609 + 318515409 = 139647^2 + 17847^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88555 + ... + 217902.

Almost surely, 2^19819800018 is an apocalyptic number.

19819800018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19819800018 is an abundant number, since it is smaller than the sum of its proper divisors (23135192010).

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

19819800018 is a wasteful number, since it uses less digits than its factorization.

19819800018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310058 (or 310055 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 45.

The spelling of 19819800018 in words is "nineteen billion, eight hundred nineteen million, eight hundred thousand, eighteen".