115666615 has 4 divisors (see below), whose sum is σ = 138799944. Its totient is φ = 92533288.

The previous prime is 115666601. The next prime is 115666619. The reversal of 115666615 is 516666511.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 115666615 - 2¹⁹ = 115142327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115666619) 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, 11566657 + ... + 11566666.

It is an arithmetic number, because the mean of its divisors is an integer number (34699986).

Almost surely, 2^115666615 is an apocalyptic number.

115666615 is a deficient number, since it is larger than the sum of its proper divisors (23133329).

115666615 is an equidigital number, since it uses as much as digits as its factorization.

115666615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23133328.

The product of its digits is 32400, while the sum is 37.

The square root of 115666615 is about 10754.8414679157. The cubic root of 115666615 is about 487.2322298933.

It can be divided in two parts, 115666 and 615, that added together give a square (116281 = 341²).

The spelling of 115666615 in words is "one hundred fifteen million, six hundred sixty-six thousand, six hundred fifteen".