91857859 has 2 divisors, whose sum is σ = 91857860. Its totient is φ = 91857858.

The previous prime is 91857797. The next prime is 91857901. The reversal of 91857859 is 95875819.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91857859 - 2¹⁵ = 91825091 is a prime.

It is not a weakly prime, because it can be changed into another prime (91857959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45928929 + 45928930.

It is an arithmetic number, because the mean of its divisors is an integer number (45928930).

Almost surely, 2^91857859 is an apocalyptic number.

91857859 is a deficient number, since it is larger than the sum of its proper divisors (1).

91857859 is an equidigital number, since it uses as much as digits as its factorization.

91857859 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 907200, while the sum is 52.

The square root of 91857859 is about 9584.2505705976. The cubic root of 91857859 is about 451.2031326672.

The spelling of 91857859 in words is "ninety-one million, eight hundred fifty-seven thousand, eight hundred fifty-nine".