91421161 has 4 divisors (see below), whose sum is σ = 98453572. Its totient is φ = 84388752.

The previous prime is 91421153. The next prime is 91421219. The reversal of 91421161 is 16112419.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16112419 = 223 ⋅72253.

It can be written as a sum of positive squares in 2 ways, for example, as 43811161 + 47610000 = 6619^2 + 6900^2 .

It is a cyclic number.

It is not a de Polignac number, because 91421161 - 2³ = 91421153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91421861) 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, 3516186 + ... + 3516211.

It is an arithmetic number, because the mean of its divisors is an integer number (24613393).

Almost surely, 2^91421161 is an apocalyptic number.

It is an amenable number.

91421161 is a deficient number, since it is larger than the sum of its proper divisors (7032411).

91421161 is a wasteful number, since it uses less digits than its factorization.

91421161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7032410.

The product of its digits is 432, while the sum is 25.

The square root of 91421161 is about 9561.4413662376. The cubic root of 91421161 is about 450.4869806285.

The spelling of 91421161 in words is "ninety-one million, four hundred twenty-one thousand, one hundred sixty-one".