91660115 has 4 divisors (see below), whose sum is σ = 109992144. Its totient is φ = 73328088.

The previous prime is 91660111. The next prime is 91660117. The reversal of 91660115 is 51106619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51106619 = 1973 ⋅25903.

It is a cyclic number.

It is not a de Polignac number, because 91660115 - 2² = 91660111 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91660111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9166007 + ... + 9166016.

It is an arithmetic number, because the mean of its divisors is an integer number (27498036).

Almost surely, 2^91660115 is an apocalyptic number.

91660115 is a deficient number, since it is larger than the sum of its proper divisors (18332029).

91660115 is a wasteful number, since it uses less digits than its factorization.

91660115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18332028.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 91660115 is about 9573.9289218168. The cubic root of 91660115 is about 450.8791291337.

The spelling of 91660115 in words is "ninety-one million, six hundred sixty thousand, one hundred fifteen".