261443239 has 2 divisors, whose sum is σ = 261443240. Its totient is φ = 261443238.

The previous prime is 261443201. The next prime is 261443251. The reversal of 261443239 is 932344162.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261443239 - 2¹³ = 261435047 is a prime.

It is a super-2 number, since 2×261443239² = 136705134437622242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261443279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130721619 + 130721620.

It is an arithmetic number, because the mean of its divisors is an integer number (130721620).

Almost surely, 2^261443239 is an apocalyptic number.

261443239 is a deficient number, since it is larger than the sum of its proper divisors (1).

261443239 is an equidigital number, since it uses as much as digits as its factorization.

261443239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 34.

The square root of 261443239 is about 16169.2065049587. The cubic root of 261443239 is about 639.4292103258.

The spelling of 261443239 in words is "two hundred sixty-one million, four hundred forty-three thousand, two hundred thirty-nine".