19899984877 has 2 divisors, whose sum is σ = 19899984878. Its totient is φ = 19899984876.

The previous prime is 19899984857. The next prime is 19899984883. The reversal of 19899984877 is 77848999891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15931740841 + 3968244036 = 126221^2 + 62994^2 .

It is a cyclic number.

It is not a de Polignac number, because 19899984877 - 2²⁷ = 19765767149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19899984797 and 19899984806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19899984827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949992438 + 9949992439.

It is an arithmetic number, because the mean of its divisors is an integer number (9949992439).

Almost surely, 2^19899984877 is an apocalyptic number.

It is an amenable number.

19899984877 is a deficient number, since it is larger than the sum of its proper divisors (1).

19899984877 is an equidigital number, since it uses as much as digits as its factorization.

19899984877 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 658409472, while the sum is 79.

The spelling of 19899984877 in words is "nineteen billion, eight hundred ninety-nine million, nine hundred eighty-four thousand, eight hundred seventy-seven".