1668199 has 6 divisors (see below), whose sum is σ = 1806576. Its totient is φ = 1539720.

The previous prime is 1668197. The next prime is 1668211. The reversal of 1668199 is 9918661.

1668199 = 106² + 107² + ... + 183².

It is not a de Polignac number, because 1668199 - 2¹ = 1668197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668197) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4767 + ... + 5104.

It is an arithmetic number, because the mean of its divisors is an integer number (301096).

2^1668199 is an apocalyptic number.

1668199 is a deficient number, since it is larger than the sum of its proper divisors (138377).

1668199 is an equidigital number, since it uses as much as digits as its factorization.

1668199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9897 (or 9884 counting only the distinct ones).

The product of its digits is 23328, while the sum is 40.

The square root of 1668199 is about 1291.5877825374. The cubic root of 1668199 is about 118.5994346608.

The spelling of 1668199 in words is "one million, six hundred sixty-eight thousand, one hundred ninety-nine".