1680105 has 16 divisors (see below), whose sum is σ = 3072384. Its totient is φ = 768000.

The previous prime is 1680103. The next prime is 1680121. The reversal of 1680105 is 5010861.

It is not a de Polignac number, because 1680105 - 2¹ = 1680103 is a prime.

It is a super-3 number, since 3×1680105³ = 14227563334701472875, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an Ulam number.

It is a Curzon number.

1680105 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680101) 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 15 ways as a sum of consecutive naturals, for example, 7896 + ... + 8105.

It is an arithmetic number, because the mean of its divisors is an integer number (192024).

2^1680105 is an apocalyptic number.

1680105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1680105 is a deficient number, since it is larger than the sum of its proper divisors (1392279).

1680105 is a wasteful number, since it uses less digits than its factorization.

1680105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16016.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 1680105 is about 1296.1886436781. The cubic root of 1680105 is about 118.8809156378.

Adding to 1680105 its reverse (5010861), we get a palindrome (6690966).

It can be divided in two parts, 1680 and 105, that multiplied together give a square (176400 = 420²).

The spelling of 1680105 in words is "one million, six hundred eighty thousand, one hundred five".