663320 has 64 divisors (see below), whose sum is σ = 1797120. Its totient is φ = 215424.

The previous prime is 663319. The next prime is 663331. The reversal of 663320 is 23366.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an Ulam number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 663292 and 663301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6389 + ... + 6491.

It is an arithmetic number, because the mean of its divisors is an integer number (28080).

2⁶⁶³³²⁰ 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 663320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (898560).

663320 is an abundant number, since it is smaller than the sum of its proper divisors (1133800).

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

663320 is a wasteful number, since it uses less digits than its factorization.

663320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

The square root of 663320 is about 814.4445960285. Note that the first 3 decimals coincide. The cubic root of 663320 is about 87.2116220516.

Adding to 663320 its reverse (23366), we get a palindrome (686686).

The spelling of 663320 in words is "six hundred sixty-three thousand, three hundred twenty".