91749321 has 8 divisors (see below), whose sum is σ = 135924960. Its totient is φ = 61166196.

The previous prime is 91749319. The next prime is 91749353. The reversal of 91749321 is 12394719.

It is not a de Polignac number, because 91749321 - 2¹ = 91749319 is a prime.

It is a super-2 number, since 2×91749321² = 16835875807922082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91749521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1699035 + ... + 1699088.

It is an arithmetic number, because the mean of its divisors is an integer number (16990620).

Almost surely, 2^91749321 is an apocalyptic number.

It is an amenable number.

91749321 is a deficient number, since it is larger than the sum of its proper divisors (44175639).

91749321 is a wasteful number, since it uses less digits than its factorization.

91749321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3398132 (or 3398126 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 91749321 is about 9578.5865867569. The cubic root of 91749321 is about 451.0253507939.

The spelling of 91749321 in words is "ninety-one million, seven hundred forty-nine thousand, three hundred twenty-one".