116186991 has 4 divisors (see below), whose sum is σ = 154915992. Its totient is φ = 77457992.

The previous prime is 116186953. The next prime is 116187011. The reversal of 116186991 is 199681611.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199681611 = 3 ⋅66560537.

It is a cyclic number.

It is not a de Polignac number, because 116186991 - 2¹⁰ = 116185967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (116186921) 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, 19364496 + ... + 19364501.

It is an arithmetic number, because the mean of its divisors is an integer number (38728998).

Almost surely, 2^116186991 is an apocalyptic number.

116186991 is a deficient number, since it is larger than the sum of its proper divisors (38729001).

116186991 is an equidigital number, since it uses as much as digits as its factorization.

116186991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38729000.

The product of its digits is 23328, while the sum is 42.

The square root of 116186991 is about 10779.0069579716. The cubic root of 116186991 is about 487.9618114320.

The spelling of 116186991 in words is "one hundred sixteen million, one hundred eighty-six thousand, nine hundred ninety-one".