261445271 has 2 divisors, whose sum is σ = 261445272. Its totient is φ = 261445270.

The previous prime is 261445141. The next prime is 261445273. The reversal of 261445271 is 172544162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261445271 - 2¹⁰ = 261444247 is a prime.

Together with 261445273, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261445273) 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, 130722635 + 130722636.

It is an arithmetic number, because the mean of its divisors is an integer number (130722636).

Almost surely, 2^261445271 is an apocalyptic number.

261445271 is a deficient number, since it is larger than the sum of its proper divisors (1).

261445271 is an equidigital number, since it uses as much as digits as its factorization.

261445271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 32.

The square root of 261445271 is about 16169.2693403258. The cubic root of 261445271 is about 639.4308669209.

The spelling of 261445271 in words is "two hundred sixty-one million, four hundred forty-five thousand, two hundred seventy-one".