1680557 has 2 divisors, whose sum is σ = 1680558. Its totient is φ = 1680556.

The previous prime is 1680551. The next prime is 1680583. The reversal of 1680557 is 7550861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 872356 + 808201 = 934^2 + 899^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680557 - 2¹⁰ = 1679533 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1680551) 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 as a sum of consecutive naturals, namely, 840278 + 840279.

It is an arithmetic number, because the mean of its divisors is an integer number (840279).

2^1680557 is an apocalyptic number.

It is an amenable number.

1680557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680557 is an equidigital number, since it uses as much as digits as its factorization.

1680557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 1680557 is about 1296.3629892897. The cubic root of 1680557 is about 118.8915755581.

The spelling of 1680557 in words is "one million, six hundred eighty thousand, five hundred fifty-seven".