261841 has 4 divisors (see below), whose sum is σ = 270900. Its totient is φ = 252784.

The previous prime is 261823. The next prime is 261847. The reversal of 261841 is 148162.

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 221841 + 40000 = 471^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 261841 - 2⁷ = 261713 is a prime.

It is a Duffinian number.

261841 is a lucky number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (261847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4486 + ... + 4543.

It is an arithmetic number, because the mean of its divisors is an integer number (67725).

2²⁶¹⁸⁴¹ is an apocalyptic number.

It is an amenable number.

261841 is a deficient number, since it is larger than the sum of its proper divisors (9059).

261841 is an equidigital number, since it uses as much as digits as its factorization.

261841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9058.

The product of its digits is 384, while the sum is 22.

The square root of 261841 is about 511.7040160093. The cubic root of 261841 is about 63.9753322903.

The spelling of 261841 in words is "two hundred sixty-one thousand, eight hundred forty-one".