1720679 has 2 divisors, whose sum is σ = 1720680. Its totient is φ = 1720678.

The previous prime is 1720669. The next prime is 1720703. The reversal of 1720679 is 9760271.

It is a weak prime.

It is an emirp because it is prime and its reverse (9760271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1720679 - 2²⁰ = 672103 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1720619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860339 + 860340.

It is an arithmetic number, because the mean of its divisors is an integer number (860340).

2^1720679 is an apocalyptic number.

1720679 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720679 is an equidigital number, since it uses as much as digits as its factorization.

1720679 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 1720679 is about 1311.7465456406. The cubic root of 1720679 is about 119.8302925153.

The spelling of 1720679 in words is "one million, seven hundred twenty thousand, six hundred seventy-nine".