1680345 has 28 divisors (see below), whose sum is σ = 3029796. Its totient is φ = 894240.

The previous prime is 1680323. The next prime is 1680359. The reversal of 1680345 is 5430861.

It can be written as a sum of positive squares in 2 ways, for example, as 571536 + 1108809 = 756^2 + 1053^2 .

It is not a de Polignac number, because 1680345 - 2⁵ = 1680313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a d-powerful number, because it can be written as 1 + 6⁸ + 8³ + 0 + 3³ + 4³ + 5³ .

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 3415 + ... + 3875.

It is an arithmetic number, because the mean of its divisors is an integer number (108207).

2^1680345 is an apocalyptic number.

1680345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1680345 is a deficient number, since it is larger than the sum of its proper divisors (1349451).

1680345 is an frugal number, since it uses more digits than its factorization.

1680345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1680345 is about 1296.2812194890. The cubic root of 1680345 is about 118.8865760105.

It can be divided in two parts, 1680 and 345, that added together give a square (2025 = 45²).

The spelling of 1680345 in words is "one million, six hundred eighty thousand, three hundred forty-five".