256241569 has 2 divisors, whose sum is σ = 256241570. Its totient is φ = 256241568.

The previous prime is 256241549. The next prime is 256241621. The reversal of 256241569 is 965142652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 152201569 + 104040000 = 12337^2 + 10200^2 .

It is a cyclic number.

It is not a de Polignac number, because 256241569 - 2⁷ = 256241441 is a prime.

It is a super-4 number, since 4×256241569⁴ (a number of 35 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256241549) 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, 128120784 + 128120785.

It is an arithmetic number, because the mean of its divisors is an integer number (128120785).

Almost surely, 2^256241569 is an apocalyptic number.

It is an amenable number.

256241569 is a deficient number, since it is larger than the sum of its proper divisors (1).

256241569 is an equidigital number, since it uses as much as digits as its factorization.

256241569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 40.

The square root of 256241569 is about 16007.5472512187. The cubic root of 256241569 is about 635.1600803347.

The spelling of 256241569 in words is "two hundred fifty-six million, two hundred forty-one thousand, five hundred sixty-nine".