840709 has 2 divisors, whose sum is σ = 840710. Its totient is φ = 840708.

The previous prime is 840703. The next prime is 840713. The reversal of 840709 is 907048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 804609 + 36100 = 897^2 + 190^2 .

It is a cyclic number.

It is not a de Polignac number, because 840709 - 2⁹ = 840197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840703) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420354 + 420355.

It is an arithmetic number, because the mean of its divisors is an integer number (420355).

2⁸⁴⁰⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

840709 is a deficient number, since it is larger than the sum of its proper divisors (1).

840709 is an equidigital number, since it uses as much as digits as its factorization.

840709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 840709 is about 916.9018486185. The cubic root of 840709 is about 94.3804185302.

The spelling of 840709 in words is "eight hundred forty thousand, seven hundred nine".