91173983 has 2 divisors, whose sum is σ = 91173984. Its totient is φ = 91173982.

The previous prime is 91173977. The next prime is 91173991. The reversal of 91173983 is 38937119.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91173983 - 2⁴ = 91173967 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91173983.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91173083) 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 as a sum of consecutive naturals, namely, 45586991 + 45586992.

It is an arithmetic number, because the mean of its divisors is an integer number (45586992).

Almost surely, 2^91173983 is an apocalyptic number.

91173983 is a deficient number, since it is larger than the sum of its proper divisors (1).

91173983 is an equidigital number, since it uses as much as digits as its factorization.

91173983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 41.

The square root of 91173983 is about 9548.5068466227. The cubic root of 91173983 is about 450.0806160097.

The spelling of 91173983 in words is "ninety-one million, one hundred seventy-three thousand, nine hundred eighty-three".