6663 has 4 divisors (see below), whose sum is σ = 8888. Its totient is φ = 4440.

The previous prime is 6661. The next prime is 6673. The reversal of 6663 is 3666.

6663 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

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

It is not a de Polignac number, because 6663 - 2¹ = 6661 is a prime.

It is a D-number.

It is a Duffinian number.

6663 is a lucky number.

It is a plaindrome in base 14.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1108 + ... + 1113.

It is an arithmetic number, because the mean of its divisors is an integer number (2222).

2⁶⁶⁶³ is an apocalyptic number.

6663 is a deficient number, since it is larger than the sum of its proper divisors (2225).

6663 is a wasteful number, since it uses less digits than its factorization.

6663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2224.

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

The square root of 6663 is about 81.6272013486. The cubic root of 6663 is about 18.8172694794.

The spelling of 6663 in words is "six thousand, six hundred sixty-three".