261317 has 6 divisors (see below), whose sum is σ = 304038. Its totient is φ = 223944.

The previous prime is 261301. The next prime is 261323. The reversal of 261317 is 713162.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 261121 + 196 = 511^2 + 14^2 .

It is not a de Polignac number, because 261317 - 2⁴ = 261301 is a prime.

It is a super-4 number, since 4×261317⁴ (a number of 23 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261317.

It is not an unprimeable number, because it can be changed into a prime (261337) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2618 + ... + 2715.

It is an arithmetic number, because the mean of its divisors is an integer number (50673).

2²⁶¹³¹⁷ is an apocalyptic number.

It is an amenable number.

261317 is a deficient number, since it is larger than the sum of its proper divisors (42721).

261317 is an equidigital number, since it uses as much as digits as its factorization.

261317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5347 (or 5340 counting only the distinct ones).

The product of its digits is 252, while the sum is 20.

The square root of 261317 is about 511.1917448473. The cubic root of 261317 is about 63.9326276702.

Adding to 261317 its reverse (713162), we get a palindrome (974479).

The spelling of 261317 in words is "two hundred sixty-one thousand, three hundred seventeen".