91786491 has 12 divisors (see below), whose sum is σ = 138345168. Its totient is φ = 58530384.

The previous prime is 91786481. The next prime is 91786507. The reversal of 91786491 is 19468719.

It is a happy number.

91786491 is a `hidden beast` number, since 91 + 78 + 6 + 491 = 666.

It is not a de Polignac number, because 91786491 - 2¹⁵ = 91753723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91786411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221500 + ... + 221913.

It is an arithmetic number, because the mean of its divisors is an integer number (11528764).

Almost surely, 2^91786491 is an apocalyptic number.

91786491 is a deficient number, since it is larger than the sum of its proper divisors (46558677).

91786491 is a wasteful number, since it uses less digits than its factorization.

91786491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443442 (or 443439 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 91786491 is about 9580.5266556698. The cubic root of 91786491 is about 451.0862498780.

The spelling of 91786491 in words is "ninety-one million, seven hundred eighty-six thousand, four hundred ninety-one".