261185 has 4 divisors (see below), whose sum is σ = 313428. Its totient is φ = 208944.

The previous prime is 261169. The next prime is 261223. The reversal of 261185 is 581162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 97969 + 163216 = 313^2 + 404^2 .

It is a cyclic number.

It is not a de Polignac number, because 261185 - 2⁴ = 261169 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261185.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26114 + ... + 26123.

It is an arithmetic number, because the mean of its divisors is an integer number (78357).

2²⁶¹¹⁸⁵ is an apocalyptic number.

It is an amenable number.

261185 is a deficient number, since it is larger than the sum of its proper divisors (52243).

261185 is an equidigital number, since it uses as much as digits as its factorization.

261185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52242.

The product of its digits is 480, while the sum is 23.

The square root of 261185 is about 511.0626184725. The cubic root of 261185 is about 63.9218610175.

Subtracting from 261185 its sum of digits (23), we obtain a palindrome (261162).

The spelling of 261185 in words is "two hundred sixty-one thousand, one hundred eighty-five".