99857 has 4 divisors (see below), whose sum is σ = 101556. Its totient is φ = 98160.

The previous prime is 99839. The next prime is 99859. The reversal of 99857 is 75899.

It is a Cunningham number, because it is equal to 316²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75899 = 71 ⋅1069.

It can be written as a sum of positive squares in 2 ways, for example, as 3136 + 96721 = 56^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 99857 - 2⁶ = 99793 is a prime.

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 99857.

It is not an unprimeable number, because it can be changed into a prime (99859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 758 + ... + 879.

It is an arithmetic number, because the mean of its divisors is an integer number (25389).

2⁹⁹⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

99857 is a deficient number, since it is larger than the sum of its proper divisors (1699).

99857 is a wasteful number, since it uses less digits than its factorization.

99857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1698.

The product of its digits is 22680, while the sum is 38.

The square root of 99857 is about 316.0015822745. The cubic root of 99857 is about 46.3937528748.

Subtracting from 99857 its product of digits (22680), we obtain a palindrome (77177).

The spelling of 99857 in words is "ninety-nine thousand, eight hundred fifty-seven".