321316663 has 4 divisors (see below), whose sum is σ = 321358968. Its totient is φ = 321274360.

The previous prime is 321316603. The next prime is 321316691. The reversal of 321316663 is 366613123.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321316663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321316603) 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 3 ways as a sum of consecutive naturals, for example, 6268 + ... + 26113.

It is an arithmetic number, because the mean of its divisors is an integer number (80339742).

Almost surely, 2^321316663 is an apocalyptic number.

321316663 is a deficient number, since it is larger than the sum of its proper divisors (42305).

321316663 is an equidigital number, since it uses as much as digits as its factorization.

321316663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42304.

The product of its digits is 11664, while the sum is 31.

The square root of 321316663 is about 17925.3078913585. The cubic root of 321316663 is about 684.9272041561.

Adding to 321316663 its reverse (366613123), we get a palindrome (687929786).

The spelling of 321316663 in words is "three hundred twenty-one million, three hundred sixteen thousand, six hundred sixty-three".