91159973 has 2 divisors, whose sum is σ = 91159974. Its totient is φ = 91159972.

The previous prime is 91159969. The next prime is 91160011. The reversal of 91159973 is 37995119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50225569 + 40934404 = 7087^2 + 6398^2 .

It is a cyclic number.

It is not a de Polignac number, because 91159973 - 2² = 91159969 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91159903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45579986 + 45579987.

It is an arithmetic number, because the mean of its divisors is an integer number (45579987).

Almost surely, 2^91159973 is an apocalyptic number.

It is an amenable number.

91159973 is a deficient number, since it is larger than the sum of its proper divisors (1).

91159973 is an equidigital number, since it uses as much as digits as its factorization.

91159973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 76545, while the sum is 44.

The square root of 91159973 is about 9547.7731958819. The cubic root of 91159973 is about 450.0575613611.

The spelling of 91159973 in words is "ninety-one million, one hundred fifty-nine thousand, nine hundred seventy-three".