266561567 has 2 divisors, whose sum is σ = 266561568. Its totient is φ = 266561566.

The previous prime is 266561543. The next prime is 266561569. The reversal of 266561567 is 765165662.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 266561567 - 2¹² = 266557471 is a prime.

Together with 266561569, 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 (266561569) 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, 133280783 + 133280784.

It is an arithmetic number, because the mean of its divisors is an integer number (133280784).

Almost surely, 2^266561567 is an apocalyptic number.

266561567 is a deficient number, since it is larger than the sum of its proper divisors (1).

266561567 is an equidigital number, since it uses as much as digits as its factorization.

266561567 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 453600, while the sum is 44.

The square root of 266561567 is about 16326.7132944754. The cubic root of 266561567 is about 643.5750181151.

The spelling of 266561567 in words is "two hundred sixty-six million, five hundred sixty-one thousand, five hundred sixty-seven".