91081673 has 2 divisors, whose sum is σ = 91081674. Its totient is φ = 91081672.

The previous prime is 91081651. The next prime is 91081759. The reversal of 91081673 is 37618019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78712384 + 12369289 = 8872^2 + 3517^2 .

It is an emirp because it is prime and its reverse (37618019) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91081673 - 2¹² = 91077577 is a prime.

It is not a weakly prime, because it can be changed into another prime (91081643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45540836 + 45540837.

It is an arithmetic number, because the mean of its divisors is an integer number (45540837).

Almost surely, 2^91081673 is an apocalyptic number.

It is an amenable number.

91081673 is a deficient number, since it is larger than the sum of its proper divisors (1).

91081673 is an equidigital number, since it uses as much as digits as its factorization.

91081673 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 91081673 is about 9543.6718824570. The cubic root of 91081673 is about 449.9286685289.

The spelling of 91081673 in words is "ninety-one million, eighty-one thousand, six hundred seventy-three".