320640857 has 2 divisors, whose sum is σ = 320640858. Its totient is φ = 320640856.

The previous prime is 320640851. The next prime is 320640863. The reversal of 320640857 is 758046023.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (320640851) and next prime (320640863).

It can be written as a sum of positive squares in only one way, i.e., 208196041 + 112444816 = 14429^2 + 10604^2 .

It is a cyclic number.

It is not a de Polignac number, because 320640857 - 2²² = 316446553 is a prime.

It is not a weakly prime, because it can be changed into another prime (320640851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160320428 + 160320429.

It is an arithmetic number, because the mean of its divisors is an integer number (160320429).

Almost surely, 2^320640857 is an apocalyptic number.

It is an amenable number.

320640857 is a deficient number, since it is larger than the sum of its proper divisors (1).

320640857 is an equidigital number, since it uses as much as digits as its factorization.

320640857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 320640857 is about 17906.4473584237. The cubic root of 320640857 is about 684.4466783886.

The spelling of 320640857 in words is "three hundred twenty million, six hundred forty thousand, eight hundred fifty-seven".