1663330321 has 2 divisors, whose sum is σ = 1663330322. Its totient is φ = 1663330320.

The previous prime is 1663330309. The next prime is 1663330373. The reversal of 1663330321 is 1230333661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1056250000 + 607080321 = 32500^2 + 24639^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663330321 - 2⁹ = 1663329809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1663330321.

It is not a weakly prime, because it can be changed into another prime (1663330391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831665160 + 831665161.

It is an arithmetic number, because the mean of its divisors is an integer number (831665161).

Almost surely, 2^1663330321 is an apocalyptic number.

It is an amenable number.

1663330321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663330321 is an equidigital number, since it uses as much as digits as its factorization.

1663330321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 28.

The square root of 1663330321 is about 40783.9468541239. The cubic root of 1663330321 is about 1184.8394379713.

Adding to 1663330321 its reverse (1230333661), we get a palindrome (2893663982).

The spelling of 1663330321 in words is "one billion, six hundred sixty-three million, three hundred thirty thousand, three hundred twenty-one".