663989824 has 21 divisors (see below), whose sum is σ = 1318014001. Its totient is φ = 331891840.

The previous prime is 663989813. The next prime is 663989831. The reversal of 663989824 is 428989366.

It is a happy number.

The square root of 663989824 is 25768.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 512207424 + 151782400 = 22632^2 + 12320^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 204534 + ... + 207754.

Almost surely, 2^663989824 is an apocalyptic number.

663989824 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

663989824 is the 25768-th square number.

It is an amenable number.

663989824 is a deficient number, since it is larger than the sum of its proper divisors (654024177).

663989824 is an frugal number, since it uses more digits than its factorization.

663989824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6454 (or 3223 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 55.

The cubic root of 663989824 is about 872.4096775984.

The spelling of 663989824 in words is "six hundred sixty-three million, nine hundred eighty-nine thousand, eight hundred twenty-four".