261443311 has 8 divisors (see below), whose sum is σ = 270913280. Its totient is φ = 252127512.

The previous prime is 261443291. The next prime is 261443317. The reversal of 261443311 is 113344162.

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 261443311 - 2⁵ = 261443279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261443317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35085 + ... + 41878.

It is an arithmetic number, because the mean of its divisors is an integer number (33864160).

Almost surely, 2^261443311 is an apocalyptic number.

261443311 is a deficient number, since it is larger than the sum of its proper divisors (9469969).

261443311 is an equidigital number, since it uses as much as digits as its factorization.

261443311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77085.

The product of its digits is 1728, while the sum is 25.

The square root of 261443311 is about 16169.2087314129. The cubic root of 261443311 is about 639.4292690242.

Adding to 261443311 its reverse (113344162), we get a palindrome (374787473).

The spelling of 261443311 in words is "two hundred sixty-one million, four hundred forty-three thousand, three hundred eleven".