261644353 has 8 divisors (see below), whose sum is σ = 269078760. Its totient is φ = 254229120.

The previous prime is 261644281. The next prime is 261644359. The reversal of 261644353 is 353446162.

It can be written as a sum of positive squares in 4 ways, for example, as 99540529 + 162103824 = 9977^2 + 12732^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 261644353 - 2⁹ = 261643841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261644359) 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, 25563 + ... + 34303.

It is an arithmetic number, because the mean of its divisors is an integer number (33634845).

Almost surely, 2^261644353 is an apocalyptic number.

It is an amenable number.

261644353 is a deficient number, since it is larger than the sum of its proper divisors (7434407).

261644353 is an equidigital number, since it uses as much as digits as its factorization.

261644353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9587.

The product of its digits is 51840, while the sum is 34.

The square root of 261644353 is about 16175.4243530116. The cubic root of 261644353 is about 639.5931276210.

The spelling of 261644353 in words is "two hundred sixty-one million, six hundred forty-four thousand, three hundred fifty-three".