91257 has 8 divisors (see below), whose sum is σ = 128160. Its totient is φ = 57600.

The previous prime is 91253. The next prime is 91283. The reversal of 91257 is 75219.

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

It is not a de Polignac number, because 91257 - 2² = 91253 is a prime.

91257 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91257.

It is not an unprimeable number, because it can be changed into a prime (91253) 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, 744 + ... + 857.

It is an arithmetic number, because the mean of its divisors is an integer number (16020).

2⁹¹²⁵⁷ is an apocalyptic number.

It is an amenable number.

91257 is a deficient number, since it is larger than the sum of its proper divisors (36903).

91257 is a wasteful number, since it uses less digits than its factorization.

91257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623.

The product of its digits is 630, while the sum is 24.

The square root of 91257 is about 302.0877356001. The cubic root of 91257 is about 45.0217179119.

It can be divided in two parts, 912 and 57, that multiplied together give a square (51984 = 228²).

The spelling of 91257 in words is "ninety-one thousand, two hundred fifty-seven".