320243257 has 2 divisors, whose sum is σ = 320243258. Its totient is φ = 320243256.

The previous prime is 320243249. The next prime is 320243267. The reversal of 320243257 is 752342023.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 289374121 + 30869136 = 17011^2 + 5556^2 .

It is a cyclic number.

It is not a de Polignac number, because 320243257 - 2³ = 320243249 is a prime.

It is not a weakly prime, because it can be changed into another prime (320243267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160121628 + 160121629.

It is an arithmetic number, because the mean of its divisors is an integer number (160121629).

Almost surely, 2^320243257 is an apocalyptic number.

It is an amenable number.

320243257 is a deficient number, since it is larger than the sum of its proper divisors (1).

320243257 is an equidigital number, since it uses as much as digits as its factorization.

320243257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 28.

The square root of 320243257 is about 17895.3417681809. The cubic root of 320243257 is about 684.1636529462.

The spelling of 320243257 in words is "three hundred twenty million, two hundred forty-three thousand, two hundred fifty-seven".