19491438986 has 8 divisors (see below), whose sum is σ = 29237775204. Its totient is φ = 9745513920.

The previous prime is 19491438983. The next prime is 19491439027. The reversal of 19491438986 is 68983419491.

It can be written as a sum of positive squares in 2 ways, for example, as 17498262961 + 1993176025 = 132281^2 + 44645^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (19491438983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82616 + ... + 214028.

Almost surely, 2^19491438986 is an apocalyptic number.

19491438986 is a deficient number, since it is larger than the sum of its proper divisors (9746336218).

19491438986 is a wasteful number, since it uses less digits than its factorization.

19491438986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205576.

The product of its digits is 13436928, while the sum is 62.

The spelling of 19491438986 in words is "nineteen billion, four hundred ninety-one million, four hundred thirty-eight thousand, nine hundred eighty-six".