19136820987 has 6 divisors (see below), whose sum is σ = 27642074772. Its totient is φ = 12757880652.

The previous prime is 19136820973. The next prime is 19136821013. The reversal of 19136820987 is 78902863191.

19136820987 is a `hidden beast` number, since 191 + 368 + 2 + 0 + 98 + 7 = 666.

It is not a de Polignac number, because 19136820987 - 2²⁷ = 19002603259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19136820487) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1063156713 + ... + 1063156730.

It is an arithmetic number, because the mean of its divisors is an integer number (4607012462).

Almost surely, 2^19136820987 is an apocalyptic number.

19136820987 is a deficient number, since it is larger than the sum of its proper divisors (8505253785).

19136820987 is a wasteful number, since it uses less digits than its factorization.

19136820987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2126313449 (or 2126313446 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 19136820987 in words is "nineteen billion, one hundred thirty-six million, eight hundred twenty thousand, nine hundred eighty-seven".