663616321 has 8 divisors (see below), whose sum is σ = 667966464. Its totient is φ = 659275680.

The previous prime is 663616319. The next prime is 663616337. The reversal of 663616321 is 123616366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 663616321 - 2¹ = 663616319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660616321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182901 + ... + 186493.

It is an arithmetic number, because the mean of its divisors is an integer number (83495808).

Almost surely, 2^663616321 is an apocalyptic number.

It is an amenable number.

663616321 is a deficient number, since it is larger than the sum of its proper divisors (4350143).

663616321 is a wasteful number, since it uses less digits than its factorization.

663616321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4751.

The product of its digits is 23328, while the sum is 34.

The square root of 663616321 is about 25760.7515612414. The cubic root of 663616321 is about 872.2460662814.

The spelling of 663616321 in words is "six hundred sixty-three million, six hundred sixteen thousand, three hundred twenty-one".