268649561 has 2 divisors, whose sum is σ = 268649562. Its totient is φ = 268649560.

The previous prime is 268649519. The next prime is 268649573. The reversal of 268649561 is 165946862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181413961 + 87235600 = 13469^2 + 9340^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-268649561 is a prime.

It is not a weakly prime, because it can be changed into another prime (268649581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134324780 + 134324781.

It is an arithmetic number, because the mean of its divisors is an integer number (134324781).

Almost surely, 2^268649561 is an apocalyptic number.

It is an amenable number.

268649561 is a deficient number, since it is larger than the sum of its proper divisors (1).

268649561 is an equidigital number, since it uses as much as digits as its factorization.

268649561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 47.

The square root of 268649561 is about 16390.5326637056. The cubic root of 268649561 is about 645.2510378307.

The spelling of 268649561 in words is "two hundred sixty-eight million, six hundred forty-nine thousand, five hundred sixty-one".