261812 has 24 divisors (see below), whose sum is σ = 494760. Its totient is φ = 120960.

The previous prime is 261799. The next prime is 261823. The reversal of 261812 is 218162.

261812 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 27556 + 234256 = 166^2 + 484^2 .

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 261812.

It is an unprimeable number.

261812 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 4262 + ... + 4322.

It is an arithmetic number, because the mean of its divisors is an integer number (20615).

2²⁶¹⁸¹² is an apocalyptic number.

It is an amenable number.

261812 is a deficient number, since it is larger than the sum of its proper divisors (232948).

261812 is a wasteful number, since it uses less digits than its factorization.

261812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 129 counting only the distinct ones).

The product of its digits is 192, while the sum is 20.

The square root of 261812 is about 511.6756785308. The cubic root of 261812 is about 63.9729703568.

Adding to 261812 its reverse (218162), we get a palindrome (479974).

The spelling of 261812 in words is "two hundred sixty-one thousand, eight hundred twelve".