91121593 has 4 divisors (see below), whose sum is σ = 92369908. Its totient is φ = 89873280.

The previous prime is 91121573. The next prime is 91121599. The reversal of 91121593 is 39512119.

It is a happy number.

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 33315984 + 57805609 = 5772^2 + 7603^2 .

It is a cyclic number.

It is not a de Polignac number, because 91121593 - 2⁹ = 91121081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91121599) 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, 624048 + ... + 624193.

It is an arithmetic number, because the mean of its divisors is an integer number (23092477).

Almost surely, 2^91121593 is an apocalyptic number.

It is an amenable number.

91121593 is a deficient number, since it is larger than the sum of its proper divisors (1248315).

91121593 is a wasteful number, since it uses less digits than its factorization.

91121593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248314.

The product of its digits is 2430, while the sum is 31.

The square root of 91121593 is about 9545.7630915501. The cubic root of 91121593 is about 449.9943916997.

The spelling of 91121593 in words is "ninety-one million, one hundred twenty-one thousand, five hundred ninety-three".