256810361 has 2 divisors, whose sum is σ = 256810362. Its totient is φ = 256810360.

The previous prime is 256810357. The next prime is 256810391. The reversal of 256810361 is 163018652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 244734736 + 12075625 = 15644^2 + 3475^2 .

It is a cyclic number.

It is not a de Polignac number, because 256810361 - 2² = 256810357 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256810391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128405180 + 128405181.

It is an arithmetic number, because the mean of its divisors is an integer number (128405181).

Almost surely, 2^256810361 is an apocalyptic number.

It is an amenable number.

256810361 is a deficient number, since it is larger than the sum of its proper divisors (1).

256810361 is an equidigital number, since it uses as much as digits as its factorization.

256810361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 256810361 is about 16025.3037724718. The cubic root of 256810361 is about 635.6296983732.

The spelling of 256810361 in words is "two hundred fifty-six million, eight hundred ten thousand, three hundred sixty-one".