261369 has 12 divisors (see below), whose sum is σ = 382356. Its totient is φ = 172032.

The previous prime is 261353. The next prime is 261379. The reversal of 261369 is 963162.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 131769 + 129600 = 363^2 + 360^2 .

It is not a de Polignac number, because 261369 - 2⁴ = 261353 is a prime.

It is a super-2 number, since 2×261369² = 136627508322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261329) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 889 + ... + 1145.

It is an arithmetic number, because the mean of its divisors is an integer number (31863).

2²⁶¹³⁶⁹ is an apocalyptic number.

It is an amenable number.

261369 is a deficient number, since it is larger than the sum of its proper divisors (120987).

261369 is a wasteful number, since it uses less digits than its factorization.

261369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376 (or 373 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 261369 is about 511.2426038585. The cubic root of 261369 is about 63.9368680834.

It can be divided in two parts, 261 and 369, that added together give a triangular number (630 = T₃₅).

The spelling of 261369 in words is "two hundred sixty-one thousand, three hundred sixty-nine".