115664391 has 12 divisors (see below), whose sum is σ = 170223768. Its totient is φ = 75654384.

The previous prime is 115664371. The next prime is 115664407. The reversal of 115664391 is 193466511.

115664391 is a `hidden beast` number, since 1 + 1 + 5 + 6 + 643 + 9 + 1 = 666.

It is not a de Polignac number, because 115664391 - 2⁵ = 115664359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115664371) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 120765 + ... + 121718.

It is an arithmetic number, because the mean of its divisors is an integer number (14185314).

Almost surely, 2^115664391 is an apocalyptic number.

115664391 is a deficient number, since it is larger than the sum of its proper divisors (54559377).

115664391 is a wasteful number, since it uses less digits than its factorization.

115664391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242542 (or 242539 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 115664391 is about 10754.7380721243. The cubic root of 115664391 is about 487.2291070924.

The spelling of 115664391 in words is "one hundred fifteen million, six hundred sixty-four thousand, three hundred ninety-one".