1680985 has 8 divisors (see below), whose sum is σ = 2086920. Its totient is φ = 1298304.

The previous prime is 1680983. The next prime is 1681003. The reversal of 1680985 is 5890861.

It can be written as a sum of positive squares in 4 ways, for example, as 559504 + 1121481 = 748^2 + 1059^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1680985 - 2¹ = 1680983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1680983) 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 in 7 ways as a sum of consecutive naturals, for example, 5652 + ... + 5941.

It is an arithmetic number, because the mean of its divisors is an integer number (260865).

2^1680985 is an apocalyptic number.

It is an amenable number.

1680985 is a deficient number, since it is larger than the sum of its proper divisors (405935).

1680985 is a wasteful number, since it uses less digits than its factorization.

1680985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11627.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 1680985 is about 1296.5280560019. The cubic root of 1680985 is about 118.9016677031.

The spelling of 1680985 in words is "one million, six hundred eighty thousand, nine hundred eighty-five".