261085 has 16 divisors (see below), whose sum is σ = 352512. Its totient is φ = 184000.

The previous prime is 261077. The next prime is 261089. The reversal of 261085 is 580162.

It is a happy number.

It is not a de Polignac number, because 261085 - 2³ = 261077 is a prime.

It is a Duffinian number.

261085 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2535 + ... + 2635.

It is an arithmetic number, because the mean of its divisors is an integer number (22032).

2²⁶¹⁰⁸⁵ is an apocalyptic number.

It is an amenable number.

261085 is a deficient number, since it is larger than the sum of its proper divisors (91427).

261085 is a wasteful number, since it uses less digits than its factorization.

261085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 261085 is about 510.9647737369. The cubic root of 261085 is about 63.9137020470.

It can be divided in two parts, 26 and 1085, that added together give a palindrome (1111).

The spelling of 261085 in words is "two hundred sixty-one thousand, eighty-five".