91557 has 8 divisors (see below), whose sum is σ = 135680. Its totient is φ = 61020.

The previous prime is 91541. The next prime is 91571. The reversal of 91557 is 75519.

It is not a de Polignac number, because 91557 - 2⁴ = 91541 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 3391 = 91557 / (9 + 1 + 5 + 5 + 7).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91577) 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, 1669 + ... + 1722.

It is an arithmetic number, because the mean of its divisors is an integer number (16960).

2⁹¹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

91557 is a deficient number, since it is larger than the sum of its proper divisors (44123).

91557 is a wasteful number, since it uses less digits than its factorization.

91557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3400 (or 3394 counting only the distinct ones).

The product of its digits is 1575, while the sum is 27.

The square root of 91557 is about 302.5838726700. The cubic root of 91557 is about 45.0709990330.

The spelling of 91557 in words is "ninety-one thousand, five hundred fifty-seven".