720857 has 2 divisors, whose sum is σ = 720858. Its totient is φ = 720856.

The previous prime is 720847. The next prime is 720869. The reversal of 720857 is 758027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 430336 + 290521 = 656^2 + 539^2 .

It is a cyclic number.

It is not a de Polignac number, because 720857 - 2⁶ = 720793 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (720847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360428 + 360429.

It is an arithmetic number, because the mean of its divisors is an integer number (360429).

2⁷²⁰⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

720857 is a deficient number, since it is larger than the sum of its proper divisors (1).

720857 is an equidigital number, since it uses as much as digits as its factorization.

720857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3920, while the sum is 29.

The square root of 720857 is about 849.0329793359. The cubic root of 720857 is about 89.6636416080.

The spelling of 720857 in words is "seven hundred twenty thousand, eight hundred fifty-seven".