11917986291 has 24 divisors (see below), whose sum is σ = 18063751680. Its totient is φ = 7557394416.

The previous prime is 11917986287. The next prime is 11917986293. The reversal of 11917986291 is 19268971911.

11917986291 is a `hidden beast` number, since 1 + 1 + 9 + 1 + 7 + 9 + 8 + 629 + 1 = 666.

It is not a de Polignac number, because 11917986291 - 2² = 11917986287 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11917986293) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123771 + ... + 197876.

It is an arithmetic number, because the mean of its divisors is an integer number (752656320).

Almost surely, 2^11917986291 is an apocalyptic number.

11917986291 is a deficient number, since it is larger than the sum of its proper divisors (6145765389).

11917986291 is a wasteful number, since it uses less digits than its factorization.

11917986291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321855 (or 321852 counting only the distinct ones).

The product of its digits is 489888, while the sum is 54.

The spelling of 11917986291 in words is "eleven billion, nine hundred seventeen million, nine hundred eighty-six thousand, two hundred ninety-one".