235809 has 24 divisors (see below), whose sum is σ = 411840. Its totient is φ = 127008.

The previous prime is 235793. The next prime is 235811. The reversal of 235809 is 908532.

It is not a de Polignac number, because 235809 - 2⁴ = 235793 is a prime.

It is a Curzon number.

235809 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (235849) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1099 + ... + 1295.

It is an arithmetic number, because the mean of its divisors is an integer number (17160).

2²³⁵⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

235809 is a deficient number, since it is larger than the sum of its proper divisors (176031).

235809 is a wasteful number, since it uses less digits than its factorization.

235809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 235809 is about 485.6016886297. The cubic root of 235809 is about 61.7807902088.

It can be divided in two parts, 23 and 5809, that added together give a cube (5832 = 18³).

The spelling of 235809 in words is "two hundred thirty-five thousand, eight hundred nine".