256700321 has 2 divisors, whose sum is σ = 256700322. Its totient is φ = 256700320.

The previous prime is 256700291. The next prime is 256700363. The reversal of 256700321 is 123007652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 222606400 + 34093921 = 14920^2 + 5839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256700321 is a prime.

It is not a weakly prime, because it can be changed into another prime (256700921) 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, 128350160 + 128350161.

It is an arithmetic number, because the mean of its divisors is an integer number (128350161).

Almost surely, 2^256700321 is an apocalyptic number.

It is an amenable number.

256700321 is a deficient number, since it is larger than the sum of its proper divisors (1).

256700321 is an equidigital number, since it uses as much as digits as its factorization.

256700321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 256700321 is about 16021.8700843566. The cubic root of 256700321 is about 635.5388989675.

Adding to 256700321 its reverse (123007652), we get a palindrome (379707973).

The spelling of 256700321 in words is "two hundred fifty-six million, seven hundred thousand, three hundred twenty-one".