1680257 has 4 divisors (see below), whose sum is σ = 1683780. Its totient is φ = 1676736.

The previous prime is 1680253. The next prime is 1680269. The reversal of 1680257 is 7520861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 817216 + 863041 = 904^2 + 929^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680257 - 2² = 1680253 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1680253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 908 + ... + 2045.

It is an arithmetic number, because the mean of its divisors is an integer number (420945).

2^1680257 is an apocalyptic number.

It is an amenable number.

1680257 is a deficient number, since it is larger than the sum of its proper divisors (3523).

1680257 is an equidigital number, since it uses as much as digits as its factorization.

1680257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3522.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 1680257 is about 1296.2472757927. The cubic root of 1680257 is about 118.8845006031.

The spelling of 1680257 in words is "one million, six hundred eighty thousand, two hundred fifty-seven".