19800616780 has 72 divisors (see below), whose sum is σ = 49495069008. Its totient is φ = 6630890112.

The previous prime is 19800616769. The next prime is 19800616789. The reversal of 19800616780 is 8761600891.

It is a self number, because there is not a number n which added to its sum of digits gives 19800616780.

It is not an unprimeable number, because it can be changed into a prime (19800616789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 192799 + ... + 277078.

It is an arithmetic number, because the mean of its divisors is an integer number (687431514).

Almost surely, 2^19800616780 is an apocalyptic number.

19800616780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19800616780 is an abundant number, since it is smaller than the sum of its proper divisors (29694452228).

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

19800616780 is a wasteful number, since it uses less digits than its factorization.

19800616780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469943 (or 469934 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 19800616780 in words is "nineteen billion, eight hundred million, six hundred sixteen thousand, seven hundred eighty".