663424 has 32 divisors (see below), whose sum is σ = 1358640. Its totient is φ = 322560.

The previous prime is 663409. The next prime is 663437. The reversal of 663424 is 424366.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9052 + ... + 9124.

663424 is a Friedman number, since it can be written as 32*((6+6)^4-4), using all its digits and the basic arithmetic operations.

2⁶⁶³⁴²⁴ is an apocalyptic number.

663424 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 663424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (679320).

663424 is an abundant number, since it is smaller than the sum of its proper divisors (695216).

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

663424 is an equidigital number, since it uses as much as digits as its factorization.

663424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 146 counting only the distinct ones).

The product of its digits is 3456, while the sum is 25.

The square root of 663424 is about 814.5084407175. The cubic root of 663424 is about 87.2161796984.

The spelling of 663424 in words is "six hundred sixty-three thousand, four hundred twenty-four".