91857 has 8 divisors (see below), whose sum is σ = 124576. Its totient is φ = 60192.

The previous prime is 91841. The next prime is 91867. The reversal of 91857 is 75819.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91857 - 2⁴ = 91841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28 + ... + 429.

It is an arithmetic number, because the mean of its divisors is an integer number (15572).

2⁹¹⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

91857 is a deficient number, since it is larger than the sum of its proper divisors (32719).

91857 is a wasteful number, since it uses less digits than its factorization.

91857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527.

The product of its digits is 2520, while the sum is 30.

The square root of 91857 is about 303.0791975705. The cubic root of 91857 is about 45.1201726202.

It can be divided in two parts, 918 and 57, that multiplied together give a triangular number (52326 = T₃₂₃).

The spelling of 91857 in words is "ninety-one thousand, eight hundred fifty-seven".