1690309 has 2 divisors, whose sum is σ = 1690310. Its totient is φ = 1690308.

The previous prime is 1690303. The next prime is 1690313. The reversal of 1690309 is 9030961.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1682209 + 8100 = 1297^2 + 90^2 .

It is a cyclic number.

It is not a de Polignac number, because 1690309 - 2⁵ = 1690277 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1690303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845154 + 845155.

It is an arithmetic number, because the mean of its divisors is an integer number (845155).

2^1690309 is an apocalyptic number.

It is an amenable number.

1690309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1690309 is an equidigital number, since it uses as much as digits as its factorization.

1690309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 1690309 is about 1300.1188407219. The cubic root of 1690309 is about 119.1211016783.

The spelling of 1690309 in words is "one million, six hundred ninety thousand, three hundred nine".