1680979 has 2 divisors, whose sum is σ = 1680980. Its totient is φ = 1680978.

The previous prime is 1680967. The next prime is 1680983. The reversal of 1680979 is 9790861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1680979 - 2¹³ = 1672787 is a prime.

1680979 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1680919) 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, 840489 + 840490.

It is an arithmetic number, because the mean of its divisors is an integer number (840490).

2^1680979 is an apocalyptic number.

1680979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680979 is an equidigital number, since it uses as much as digits as its factorization.

1680979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 1680979 is about 1296.5257421278. The cubic root of 1680979 is about 118.9015262363.

The spelling of 1680979 in words is "one million, six hundred eighty thousand, nine hundred seventy-nine".