85309 has 6 divisors (see below), whose sum is σ = 99294. Its totient is φ = 73080.

The previous prime is 85303. The next prime is 85313. The reversal of 85309 is 90358.

85309 is nontrivially palindromic in base 6.

It can be written as a sum of positive squares in only one way, i.e., 44100 + 41209 = 210^2 + 203^2 .

It is not a de Polignac number, because 85309 - 2¹⁵ = 52541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85303) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 822 + ... + 919.

It is an arithmetic number, because the mean of its divisors is an integer number (16549).

2⁸⁵³⁰⁹ is an apocalyptic number.

It is an amenable number.

85309 is a deficient number, since it is larger than the sum of its proper divisors (13985).

85309 is a wasteful number, since it uses less digits than its factorization.

85309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1755 (or 1748 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 85309 is about 292.0770446304. The cubic root of 85309 is about 44.0215115199.

The spelling of 85309 in words is "eighty-five thousand, three hundred nine".