663566 has 8 divisors (see below), whose sum is σ = 1009584. Its totient is φ = 327040.

The previous prime is 663563. The next prime is 663569. The reversal of 663566 is 665366.

It is an interprime number because it is at equal distance from previous prime (663563) and next prime (663569).

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

It is a Curzon number.

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 663566.

It is not an unprimeable number, because it can be changed into a prime (663563) 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, 2195 + ... + 2478.

It is an arithmetic number, because the mean of its divisors is an integer number (126198).

2⁶⁶³⁵⁶⁶ is an apocalyptic number.

663566 is a deficient number, since it is larger than the sum of its proper divisors (346018).

663566 is a wasteful number, since it uses less digits than its factorization.

663566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4746.

The product of its digits is 19440, while the sum is 32.

The square root of 663566 is about 814.5956051932. The cubic root of 663566 is about 87.2224018700. Note that the first 3 decimals are identical.

The spelling of 663566 in words is "six hundred sixty-three thousand, five hundred sixty-six".