115991161 has 8 divisors (see below), whose sum is σ = 136269504. Its totient is φ = 97335120.

The previous prime is 115991149. The next prime is 115991171. The reversal of 115991161 is 161199511.

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

It is a cyclic number.

It is not a de Polignac number, because 115991161 - 2⁷ = 115991033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115991111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405421 + ... + 405706.

It is an arithmetic number, because the mean of its divisors is an integer number (17033688).

Almost surely, 2^115991161 is an apocalyptic number.

115991161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

115991161 is a deficient number, since it is larger than the sum of its proper divisors (20278343).

115991161 is a wasteful number, since it uses less digits than its factorization.

115991161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811151.

The product of its digits is 2430, while the sum is 34.

The square root of 115991161 is about 10769.9192661784. The cubic root of 115991161 is about 487.6875084956.

The spelling of 115991161 in words is "one hundred fifteen million, nine hundred ninety-one thousand, one hundred sixty-one".