1680765 has 16 divisors (see below), whose sum is σ = 2721600. Its totient is φ = 885632.

The previous prime is 1680761. The next prime is 1680779. The reversal of 1680765 is 5670861.

1680765 = 91² + 92² + ... + 179².

It is a cyclic number.

It is not a de Polignac number, because 1680765 - 2² = 1680761 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680761) 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 15 ways as a sum of consecutive naturals, for example, 706 + ... + 1964.

It is an arithmetic number, because the mean of its divisors is an integer number (170100).

2^1680765 is an apocalyptic number.

1680765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1680765 is a deficient number, since it is larger than the sum of its proper divisors (1040835).

1680765 is a wasteful number, since it uses less digits than its factorization.

1680765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1356.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 1680765 is about 1296.4432112515. The cubic root of 1680765 is about 118.8964803659.

The spelling of 1680765 in words is "one million, six hundred eighty thousand, seven hundred sixty-five".