1680121 has 2 divisors, whose sum is σ = 1680122. Its totient is φ = 1680120.

The previous prime is 1680103. The next prime is 1680131. The reversal of 1680121 is 1210861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1590121 + 90000 = 1261^2 + 300^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680121 - 2⁵ = 1680089 is a prime.

It is not a weakly prime, because it can be changed into another prime (1680101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840060 + 840061.

It is an arithmetic number, because the mean of its divisors is an integer number (840061).

2^1680121 is an apocalyptic number.

It is an amenable number.

1680121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680121 is an equidigital number, since it uses as much as digits as its factorization.

1680121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 1680121 is about 1296.1948156045. The cubic root of 1680121 is about 118.8812930128.

Adding to 1680121 its reverse (1210861), we get a palindrome (2890982).

The spelling of 1680121 in words is "one million, six hundred eighty thousand, one hundred twenty-one".