1668197 has 2 divisors, whose sum is σ = 1668198. Its totient is φ = 1668196.

The previous prime is 1668137. The next prime is 1668211. The reversal of 1668197 is 7918661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1324801 + 343396 = 1151^2 + 586^2 .

It is an emirp because it is prime and its reverse (7918661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1668197 - 2⁶ = 1668133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1668197.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1668137) 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, 834098 + 834099.

It is an arithmetic number, because the mean of its divisors is an integer number (834099).

2^1668197 is an apocalyptic number.

It is an amenable number.

1668197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668197 is an equidigital number, since it uses as much as digits as its factorization.

1668197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The square root of 1668197 is about 1291.5870082964. The cubic root of 1668197 is about 118.5993872646.

The spelling of 1668197 in words is "one million, six hundred sixty-eight thousand, one hundred ninety-seven".