19944036818 has 16 divisors (see below), whose sum is σ = 29976148224. Its totient is φ = 9952004400.

The previous prime is 19944036809. The next prime is 19944036859. The reversal of 19944036818 is 81863044991.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 19944036818.

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, 4285793 + ... + 4290443.

It is an arithmetic number, because the mean of its divisors is an integer number (1873509264).

Almost surely, 2^19944036818 is an apocalyptic number.

19944036818 is a deficient number, since it is larger than the sum of its proper divisors (10032111406).

19944036818 is a wasteful number, since it uses less digits than its factorization.

19944036818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8497.

The product of its (nonzero) digits is 1492992, while the sum is 53.

The spelling of 19944036818 in words is "nineteen billion, nine hundred forty-four million, thirty-six thousand, eight hundred eighteen".