91918691 has 4 divisors (see below), whose sum is σ = 92030400. Its totient is φ = 91806984.

The previous prime is 91918681. The next prime is 91918703. The reversal of 91918691 is 19681919.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91918691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91918621) 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, 54611 + ... + 56268.

It is an arithmetic number, because the mean of its divisors is an integer number (23007600).

Almost surely, 2^91918691 is an apocalyptic number.

91918691 is a deficient number, since it is larger than the sum of its proper divisors (111709).

91918691 is a wasteful number, since it uses less digits than its factorization.

91918691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111708.

The product of its digits is 34992, while the sum is 44.

The square root of 91918691 is about 9587.4235850931. The cubic root of 91918691 is about 451.3027123603.

The spelling of 91918691 in words is "ninety-one million, nine hundred eighteen thousand, six hundred ninety-one".