668667 has 8 divisors (see below), whose sum is σ = 938560. Its totient is φ = 422280.

The previous prime is 668623. The next prime is 668671. The reversal of 668667 is 766866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 668667 - 2⁷ = 668539 is a prime.

It is a Duffinian number.

668667 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (668617) 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 7 ways as a sum of consecutive naturals, for example, 5809 + ... + 5922.

It is an arithmetic number, because the mean of its divisors is an integer number (117320).

2⁶⁶⁸⁶⁶⁷ is an apocalyptic number.

668667 is a deficient number, since it is larger than the sum of its proper divisors (269893).

668667 is a wasteful number, since it uses less digits than its factorization.

668667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11753.

The product of its digits is 72576, while the sum is 39.

The square root of 668667 is about 817.7206124343. The cubic root of 668667 is about 87.4453318380.

The spelling of 668667 in words is "six hundred sixty-eight thousand, six hundred sixty-seven".