1681679 has 2 divisors, whose sum is σ = 1681680. Its totient is φ = 1681678.

The previous prime is 1681661. The next prime is 1681703. The reversal of 1681679 is 9761861.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1681679 - 2⁸ = 1681423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681619) 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, 840839 + 840840.

It is an arithmetic number, because the mean of its divisors is an integer number (840840).

2^1681679 is an apocalyptic number.

1681679 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681679 is an equidigital number, since it uses as much as digits as its factorization.

1681679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The square root of 1681679 is about 1296.7956662482. The cubic root of 1681679 is about 118.9180284289.

The spelling of 1681679 in words is "one million, six hundred eighty-one thousand, six hundred seventy-nine".