19808318820 has 48 divisors (see below), whose sum is σ = 56086490880. Its totient is φ = 5222866176.

The previous prime is 19808318801. The next prime is 19808318851. The reversal of 19808318820 is 2881380891.

It is a self number, because there is not a number n which added to its sum of digits gives 19808318820.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1849372 + ... + 1860051.

It is an arithmetic number, because the mean of its divisors is an integer number (1168468560).

Almost surely, 2^19808318820 is an apocalyptic number.

19808318820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19808318820 is an abundant number, since it is smaller than the sum of its proper divisors (36278172060).

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

19808318820 is a wasteful number, since it uses less digits than its factorization.

19808318820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3709524 (or 3709522 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 48.

The spelling of 19808318820 in words is "nineteen billion, eight hundred eight million, three hundred eighteen thousand, eight hundred twenty".