261583871 has 2 divisors, whose sum is σ = 261583872. Its totient is φ = 261583870.

The previous prime is 261583841. The next prime is 261583873. The reversal of 261583871 is 178385162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261583871 - 2¹⁴ = 261567487 is a prime.

It is a super-2 number, since 2×261583871² = 136852243134689282, which contains 22 as substring.

Together with 261583873, 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 (261583873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130791935 + 130791936.

It is an arithmetic number, because the mean of its divisors is an integer number (130791936).

Almost surely, 2^261583871 is an apocalyptic number.

261583871 is a deficient number, since it is larger than the sum of its proper divisors (1).

261583871 is an equidigital number, since it uses as much as digits as its factorization.

261583871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 41.

The square root of 261583871 is about 16173.5546804034. The cubic root of 261583871 is about 639.5438408032.

The spelling of 261583871 in words is "two hundred sixty-one million, five hundred eighty-three thousand, eight hundred seventy-one".