91991374 has 8 divisors (see below), whose sum is σ = 138028320. Its totient is φ = 45981936.

The previous prime is 91991371. The next prime is 91991381. The reversal of 91991374 is 47319919.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 91991374.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91991371) 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, 7482 + ... + 15490.

It is an arithmetic number, because the mean of its divisors is an integer number (17253540).

Almost surely, 2^91991374 is an apocalyptic number.

91991374 is a deficient number, since it is larger than the sum of its proper divisors (46036946).

91991374 is a wasteful number, since it uses less digits than its factorization.

91991374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13754.

The product of its digits is 61236, while the sum is 43.

The square root of 91991374 is about 9591.2133747509. The cubic root of 91991374 is about 451.4216341038.

The spelling of 91991374 in words is "ninety-one million, nine hundred ninety-one thousand, three hundred seventy-four".