115991061 has 4 divisors (see below), whose sum is σ = 154654752. Its totient is φ = 77327372.

The previous prime is 115991059. The next prime is 115991111. The reversal of 115991061 is 160199511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 160199511 = 3 ⋅53399837.

It is a cyclic number.

It is not a de Polignac number, because 115991061 - 2¹ = 115991059 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115991011) 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, 19331841 + ... + 19331846.

It is an arithmetic number, because the mean of its divisors is an integer number (38663688).

Almost surely, 2^115991061 is an apocalyptic number.

It is an amenable number.

115991061 is a deficient number, since it is larger than the sum of its proper divisors (38663691).

115991061 is an equidigital number, since it uses as much as digits as its factorization.

115991061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38663690.

The product of its (nonzero) digits is 2430, while the sum is 33.

The square root of 115991061 is about 10769.9146236170. The cubic root of 115991061 is about 487.6873683448.

The spelling of 115991061 in words is "one hundred fifteen million, nine hundred ninety-one thousand, sixty-one".