663606 has 16 divisors (see below), whose sum is σ = 1474800. Its totient is φ = 221184.

The previous prime is 663601. The next prime is 663631. The reversal of 663606 is 606366.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 663606.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 663606.

It is not an unprimeable number, because it can be changed into a prime (663601) by changing a digit.

663606 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6091 + ... + 6198.

It is an arithmetic number, because the mean of its divisors is an integer number (92175).

2⁶⁶³⁶⁰⁶ is an apocalyptic number.

663606 is an abundant number, since it is smaller than the sum of its proper divisors (811194).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

663606 is a wasteful number, since it uses less digits than its factorization.

663606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12300 (or 12294 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 663606 is about 814.6201568829. The cubic root of 663606 is about 87.2241544342.

It can be divided in two parts, 66360 and 6, that added together give a palindrome (66366).

The spelling of 663606 in words is "six hundred sixty-three thousand, six hundred six".