91345981 has 4 divisors (see below), whose sum is σ = 96719292. Its totient is φ = 85972672.

The previous prime is 91345979. The next prime is 91346009. The reversal of 91345981 is 18954319.

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

It can be written as a sum of positive squares in 2 ways, for example, as 85729081 + 5616900 = 9259^2 + 2370^2 .

It is not a de Polignac number, because 91345981 - 2¹ = 91345979 is a prime.

It is a super-2 number, since 2×91345981² = 16688176489704722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91345931) 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, 2686630 + ... + 2686663.

It is an arithmetic number, because the mean of its divisors is an integer number (24179823).

Almost surely, 2^91345981 is an apocalyptic number.

It is an amenable number.

91345981 is a deficient number, since it is larger than the sum of its proper divisors (5373311).

91345981 is a wasteful number, since it uses less digits than its factorization.

91345981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5373310.

The product of its digits is 38880, while the sum is 40.

The square root of 91345981 is about 9557.5091420307. The cubic root of 91345981 is about 450.3634610891.

The spelling of 91345981 in words is "ninety-one million, three hundred forty-five thousand, nine hundred eighty-one".