261304279 has 2 divisors, whose sum is σ = 261304280. Its totient is φ = 261304278.

The previous prime is 261304273. The next prime is 261304339. The reversal of 261304279 is 972403162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261304279 - 2⁵ = 261304247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261304273) 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 as a sum of consecutive naturals, namely, 130652139 + 130652140.

It is an arithmetic number, because the mean of its divisors is an integer number (130652140).

Almost surely, 2^261304279 is an apocalyptic number.

261304279 is a deficient number, since it is larger than the sum of its proper divisors (1).

261304279 is an equidigital number, since it uses as much as digits as its factorization.

261304279 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 261304279 is about 16164.9088769470. The cubic root of 261304279 is about 639.3159023275.

The spelling of 261304279 in words is "two hundred sixty-one million, three hundred four thousand, two hundred seventy-nine".