91818691 has 16 divisors (see below), whose sum is σ = 98910720. Its totient is φ = 85032640.

The previous prime is 91818679. The next prime is 91818709. The reversal of 91818691 is 19681819.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 91818691 - 2⁷ = 91818563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91813691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95871 + ... + 96823.

It is an arithmetic number, because the mean of its divisors is an integer number (6181920).

Almost surely, 2^91818691 is an apocalyptic number.

91818691 is a deficient number, since it is larger than the sum of its proper divisors (7092029).

91818691 is a wasteful number, since it uses less digits than its factorization.

91818691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106.

The product of its digits is 31104, while the sum is 43.

The square root of 91818691 is about 9582.2070004775. The cubic root of 91818691 is about 451.1389928576.

The spelling of 91818691 in words is "ninety-one million, eight hundred eighteen thousand, six hundred ninety-one".