1720109 has 2 divisors, whose sum is σ = 1720110. Its totient is φ = 1720108.

The previous prime is 1720063. The next prime is 1720123. The reversal of 1720109 is 9010271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1562500 + 157609 = 1250^2 + 397^2 .

It is a cyclic number.

It is not a de Polignac number, because 1720109 - 2⁸ = 1719853 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 (1720189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860054 + 860055.

It is an arithmetic number, because the mean of its divisors is an integer number (860055).

2^1720109 is an apocalyptic number.

It is an amenable number.

1720109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720109 is an equidigital number, since it uses as much as digits as its factorization.

1720109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 1720109 is about 1311.5292600625. The cubic root of 1720109 is about 119.8170592103.

The spelling of 1720109 in words is "one million, seven hundred twenty thousand, one hundred nine".