1680705 has 48 divisors (see below), whose sum is σ = 3341520. Its totient is φ = 778752.

The previous prime is 1680703. The next prime is 1680709. The reversal of 1680705 is 5070861.

It can be written as a sum of positive squares in 8 ways, for example, as 1034289 + 646416 = 1017^2 + 804^2 .

It is not a de Polignac number, because 1680705 - 2¹ = 1680703 is a prime.

1680705 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680703) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 98857 + ... + 98873.

It is an arithmetic number, because the mean of its divisors is an integer number (69615).

2^1680705 is an apocalyptic number.

1680705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1680705 is a deficient number, since it is larger than the sum of its proper divisors (1660815).

1680705 is a wasteful number, since it uses less digits than its factorization.

1680705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 1680705 is about 1296.4200708104. The cubic root of 1680705 is about 118.8950655590.

The spelling of 1680705 in words is "one million, six hundred eighty thousand, seven hundred five".