63664 has 20 divisors (see below), whose sum is σ = 129456. Its totient is φ = 30272.

The previous prime is 63659. The next prime is 63667. The reversal of 63664 is 46636.

It is a happy number.

63664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (63667) 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, 282 + ... + 454.

2⁶³⁶⁶⁴ 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 63664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64728).

63664 is an abundant number, since it is smaller than the sum of its proper divisors (65792).

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

63664 is a wasteful number, since it uses less digits than its factorization.

63664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 198 counting only the distinct ones).

The product of its digits is 2592, while the sum is 25.

The square root of 63664 is about 252.3172606066. The cubic root of 63664 is about 39.9298771415.

It can be divided in two parts, 636 and 64, that multiplied together give a palindrome (40704).

The spelling of 63664 in words is "sixty-three thousand, six hundred sixty-four".