256563611 has 2 divisors, whose sum is σ = 256563612. Its totient is φ = 256563610.

The previous prime is 256563589. The next prime is 256563617. The reversal of 256563611 is 116365652.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256563611 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256563617) 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, 128281805 + 128281806.

It is an arithmetic number, because the mean of its divisors is an integer number (128281806).

Almost surely, 2^256563611 is an apocalyptic number.

256563611 is a deficient number, since it is larger than the sum of its proper divisors (1).

256563611 is an equidigital number, since it uses as much as digits as its factorization.

256563611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 35.

The square root of 256563611 is about 16017.6031602734. The cubic root of 256563611 is about 635.4260566837.

The spelling of 256563611 in words is "two hundred fifty-six million, five hundred sixty-three thousand, six hundred eleven".