91857793 has 2 divisors, whose sum is σ = 91857794. Its totient is φ = 91857792.

The previous prime is 91857781. The next prime is 91857797. The reversal of 91857793 is 39775819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65561409 + 26296384 = 8097^2 + 5128^2 .

It is a cyclic number.

It is not a de Polignac number, because 91857793 - 2⁹ = 91857281 is a prime.

It is not a weakly prime, because it can be changed into another prime (91857797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45928896 + 45928897.

It is an arithmetic number, because the mean of its divisors is an integer number (45928897).

Almost surely, 2^91857793 is an apocalyptic number.

It is an amenable number.

91857793 is a deficient number, since it is larger than the sum of its proper divisors (1).

91857793 is an equidigital number, since it uses as much as digits as its factorization.

91857793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 476280, while the sum is 49.

The square root of 91857793 is about 9584.2471274482. The cubic root of 91857793 is about 451.2030246038.

The spelling of 91857793 in words is "ninety-one million, eight hundred fifty-seven thousand, seven hundred ninety-three".