19899984277 has 2 divisors, whose sum is σ = 19899984278. Its totient is φ = 19899984276.

The previous prime is 19899984263. The next prime is 19899984289. The reversal of 19899984277 is 77248999891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12179550321 + 7720433956 = 110361^2 + 87866^2 .

It is a cyclic number.

It is not a de Polignac number, because 19899984277 - 2⁷ = 19899984149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19899984877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949992138 + 9949992139.

It is an arithmetic number, because the mean of its divisors is an integer number (9949992139).

Almost surely, 2^19899984277 is an apocalyptic number.

It is an amenable number.

19899984277 is a deficient number, since it is larger than the sum of its proper divisors (1).

19899984277 is an equidigital number, since it uses as much as digits as its factorization.

19899984277 is an evil number, because the sum of its binary digits is even.

The product of its digits is 164602368, while the sum is 73.

The spelling of 19899984277 in words is "nineteen billion, eight hundred ninety-nine million, nine hundred eighty-four thousand, two hundred seventy-seven".