666003 has 8 divisors (see below), whose sum is σ = 956368. Its totient is φ = 409824.

The previous prime is 665993. The next prime is 666013. The reversal of 666003 is 300666.

It is an interprime number because it is at equal distance from previous prime (665993) and next prime (666013).

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

It is not a de Polignac number, because 666003 - 2⁸ = 665747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8500 + ... + 8577.

It is an arithmetic number, because the mean of its divisors is an integer number (119546).

2⁶⁶⁶⁰⁰³ is an apocalyptic number.

666003 is a deficient number, since it is larger than the sum of its proper divisors (290365).

666003 is a wasteful number, since it uses less digits than its factorization.

666003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17093.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 666003 is about 816.0900685586. The cubic root of 666003 is about 87.3290485373.

Adding to 666003 its reverse (300666), we get a palindrome (966669).

The spelling of 666003 in words is "six hundred sixty-six thousand, three".