261131 has 8 divisors (see below), whose sum is σ = 287280. Its totient is φ = 235872.

The previous prime is 261127. The next prime is 261167. The reversal of 261131 is 131162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261131 - 2² = 261127 is a prime.

It is a super-2 number, since 2×261131² = 136378798322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 500 + ... + 878.

It is an arithmetic number, because the mean of its divisors is an integer number (35910).

2²⁶¹¹³¹ is an apocalyptic number.

261131 is a deficient number, since it is larger than the sum of its proper divisors (26149).

261131 is a wasteful number, since it uses less digits than its factorization.

261131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445.

The product of its digits is 36, while the sum is 14.

The square root of 261131 is about 511.0097846421. The cubic root of 261131 is about 63.9174554321.

Adding to 261131 its reverse (131162), we get a palindrome (392293).

It can be divided in two parts, 261 and 131, that multiplied together give a triangular number (34191 = T₂₆₁).

The spelling of 261131 in words is "two hundred sixty-one thousand, one hundred thirty-one".