19899984797 has 32 divisors (see below), whose sum is σ = 26283294720. Its totient is φ = 14586842880.

The previous prime is 19899984787. The next prime is 19899984821. The reversal of 19899984797 is 79748999891.

It is a cyclic number.

It is not a de Polignac number, because 19899984797 - 2⁴ = 19899984781 is a prime.

It is a super-2 number, since 2×19899984797² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19899984787) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4876604 + ... + 4880682.

It is an arithmetic number, because the mean of its divisors is an integer number (821352960).

Almost surely, 2^19899984797 is an apocalyptic number.

19899984797 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19899984797 is a deficient number, since it is larger than the sum of its proper divisors (6383309923).

19899984797 is a wasteful number, since it uses less digits than its factorization.

19899984797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7841.

The product of its digits is 740710656, while the sum is 80.

The spelling of 19899984797 in words is "nineteen billion, eight hundred ninety-nine million, nine hundred eighty-four thousand, seven hundred ninety-seven".