663564 has 36 divisors (see below), whose sum is σ = 1705592. Its totient is φ = 200640.

The previous prime is 663563. The next prime is 663569. The reversal of 663564 is 465366.

It is not an unprimeable number, because it can be changed into a prime (663563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1224 + ... + 1680.

2⁶⁶³⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 663564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (852796).

663564 is an abundant number, since it is smaller than the sum of its proper divisors (1042028).

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

663564 is a wasteful number, since it uses less digits than its factorization.

663564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486 (or 473 counting only the distinct ones).

The product of its digits is 12960, while the sum is 30.

The square root of 663564 is about 814.5943775892. The cubic root of 663564 is about 87.2223142400. Note that the first 3 decimals are identical.

The spelling of 663564 in words is "six hundred sixty-three thousand, five hundred sixty-four".