256565461 has 2 divisors, whose sum is σ = 256565462. Its totient is φ = 256565460.

The previous prime is 256565447. The next prime is 256565471. The reversal of 256565461 is 164565652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 222576561 + 33988900 = 14919^2 + 5830^2 .

It is a cyclic number.

It is not a de Polignac number, because 256565461 - 2⁵ = 256565429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256565471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128282730 + 128282731.

It is an arithmetic number, because the mean of its divisors is an integer number (128282731).

Almost surely, 2^256565461 is an apocalyptic number.

It is an amenable number.

256565461 is a deficient number, since it is larger than the sum of its proper divisors (1).

256565461 is an equidigital number, since it uses as much as digits as its factorization.

256565461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216000, while the sum is 40.

The square root of 256565461 is about 16017.6609091340. The cubic root of 256565461 is about 635.4275839663.

The spelling of 256565461 in words is "two hundred fifty-six million, five hundred sixty-five thousand, four hundred sixty-one".