1680643 has 2 divisors, whose sum is σ = 1680644. Its totient is φ = 1680642.

The previous prime is 1680617. The next prime is 1680647. The reversal of 1680643 is 3460861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1680643 - 2⁹ = 1680131 is a prime.

It is not a weakly prime, because it can be changed into another prime (1680647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840321 + 840322.

It is an arithmetic number, because the mean of its divisors is an integer number (840322).

2^1680643 is an apocalyptic number.

1680643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680643 is an equidigital number, since it uses as much as digits as its factorization.

1680643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1680643 is about 1296.3961585873. The cubic root of 1680643 is about 118.8936035565.

The spelling of 1680643 in words is "one million, six hundred eighty thousand, six hundred forty-three".