1668279 has 4 divisors (see below), whose sum is σ = 2224376. Its totient is φ = 1112184.

The previous prime is 1668253. The next prime is 1668299. The reversal of 1668279 is 9728661.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-1668279 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278044 + ... + 278049.

It is an arithmetic number, because the mean of its divisors is an integer number (556094).

2^1668279 is an apocalyptic number.

1668279 is a deficient number, since it is larger than the sum of its proper divisors (556097).

1668279 is an equidigital number, since it uses as much as digits as its factorization.

1668279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556096.

The product of its digits is 36288, while the sum is 39.

The square root of 1668279 is about 1291.6187517995. The cubic root of 1668279 is about 118.6013304785.

It can be divided in two parts, 16682 and 79, that added together give a palindrome (16761).

The spelling of 1668279 in words is "one million, six hundred sixty-eight thousand, two hundred seventy-nine".