1684121 has 4 divisors (see below), whose sum is σ = 1690932. Its totient is φ = 1677312.

The previous prime is 1684099. The next prime is 1684127. The reversal of 1684121 is 1214861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1214861 = 373 ⋅3257.

It can be written as a sum of positive squares in 2 ways, for example, as 1243225 + 440896 = 1115^2 + 664^2 .

It is a cyclic number.

It is not a de Polignac number, because 1684121 - 2¹⁸ = 1421977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1684127) 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 in 3 ways as a sum of consecutive naturals, for example, 3020 + ... + 3533.

It is an arithmetic number, because the mean of its divisors is an integer number (422733).

2^1684121 is an apocalyptic number.

It is an amenable number.

1684121 is a deficient number, since it is larger than the sum of its proper divisors (6811).

1684121 is an equidigital number, since it uses as much as digits as its factorization.

1684121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6810.

The product of its digits is 384, while the sum is 23.

The square root of 1684121 is about 1297.7368762580. The cubic root of 1684121 is about 118.9755616789.

Adding to 1684121 its reverse (1214861), we get a palindrome (2898982).

The spelling of 1684121 in words is "one million, six hundred eighty-four thousand, one hundred twenty-one".