255605321 has 2 divisors, whose sum is σ = 255605322. Its totient is φ = 255605320.

The previous prime is 255605299. The next prime is 255605341. The reversal of 255605321 is 123506552.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214183225 + 41422096 = 14635^2 + 6436^2 .

It is a cyclic number.

It is not a de Polignac number, because 255605321 - 2²⁶ = 188496457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (255605341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127802660 + 127802661.

It is an arithmetic number, because the mean of its divisors is an integer number (127802661).

Almost surely, 2^255605321 is an apocalyptic number.

It is an amenable number.

255605321 is a deficient number, since it is larger than the sum of its proper divisors (1).

255605321 is an equidigital number, since it uses as much as digits as its factorization.

255605321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9000, while the sum is 29.

The square root of 255605321 is about 15987.6615238127. The cubic root of 255605321 is about 634.6339436496.

The spelling of 255605321 in words is "two hundred fifty-five million, six hundred five thousand, three hundred twenty-one".