320866657 has 2 divisors, whose sum is σ = 320866658. Its totient is φ = 320866656.

The previous prime is 320866639. The next prime is 320866673. The reversal of 320866657 is 756668023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 240746256 + 80120401 = 15516^2 + 8951^2 .

It is an emirp because it is prime and its reverse (756668023) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 320866657 - 2⁷ = 320866529 is a prime.

It is not a weakly prime, because it can be changed into another prime (320866457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160433328 + 160433329.

It is an arithmetic number, because the mean of its divisors is an integer number (160433329).

Almost surely, 2^320866657 is an apocalyptic number.

It is an amenable number.

320866657 is a deficient number, since it is larger than the sum of its proper divisors (1).

320866657 is an equidigital number, since it uses as much as digits as its factorization.

320866657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 320866657 is about 17912.7512403874. The cubic root of 320866657 is about 684.6073064896.

The spelling of 320866657 in words is "three hundred twenty million, eight hundred sixty-six thousand, six hundred fifty-seven".