1680861 has 32 divisors (see below), whose sum is σ = 2838528. Its totient is φ = 861120.

The previous prime is 1680859. The next prime is 1680871.

1680861 is nontrivially palindromic in base 10.

1680861 is a nontrivial binomial coefficient, being equal to C(1834, 2).

It is not a de Polignac number, because 1680861 - 2¹ = 1680859 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12766 + ... + 12896.

It is an arithmetic number, because the mean of its divisors is an integer number (88704).

2^1680861 is an apocalyptic number.

1680861 is the 1833-rd triangular number and also the 917-th hexagonal number.

It is an amenable number.

1680861 is a deficient number, since it is larger than the sum of its proper divisors (1157667).

1680861 is a wasteful number, since it uses less digits than its factorization.

1680861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1680861 is about 1296.4802350981. The cubic root of 1680861 is about 118.8987439869.

The spelling of 1680861 in words is "one million, six hundred eighty thousand, eight hundred sixty-one".