261447871 has 2 divisors, whose sum is σ = 261447872. Its totient is φ = 261447870.

The previous prime is 261447839. The next prime is 261447889. The reversal of 261447871 is 178744162.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261447871 - 2⁵ = 261447839 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261447071) 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, 130723935 + 130723936.

It is an arithmetic number, because the mean of its divisors is an integer number (130723936).

Almost surely, 2^261447871 is an apocalyptic number.

261447871 is a deficient number, since it is larger than the sum of its proper divisors (1).

261447871 is an equidigital number, since it uses as much as digits as its factorization.

261447871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75264, while the sum is 40.

The square root of 261447871 is about 16169.3497395535. The cubic root of 261447871 is about 639.4329865675.

The spelling of 261447871 in words is "two hundred sixty-one million, four hundred forty-seven thousand, eight hundred seventy-one".