91761391 has 8 divisors (see below), whose sum is σ = 94891824. Its totient is φ = 88682880.

The previous prime is 91761331. The next prime is 91761401. The reversal of 91761391 is 19316719.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91761391 - 2²⁵ = 58206959 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91761391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91761331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9370 + ... + 16471.

It is an arithmetic number, because the mean of its divisors is an integer number (11861478).

Almost surely, 2^91761391 is an apocalyptic number.

91761391 is a deficient number, since it is larger than the sum of its proper divisors (3130433).

91761391 is a wasteful number, since it uses less digits than its factorization.

91761391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25961.

The product of its digits is 10206, while the sum is 37.

The square root of 91761391 is about 9579.2166172396. The cubic root of 91761391 is about 451.0451280057.

The spelling of 91761391 in words is "ninety-one million, seven hundred sixty-one thousand, three hundred ninety-one".