663011321 has 4 divisors (see below), whose sum is σ = 757727232. Its totient is φ = 568295412.

The previous prime is 663011303. The next prime is 663011347. The reversal of 663011321 is 123110366.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 123110366 = 2 ⋅61555183.

It is a cyclic number.

It is not a de Polignac number, because 663011321 - 2¹⁰ = 663010297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663011381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47357945 + ... + 47357958.

It is an arithmetic number, because the mean of its divisors is an integer number (189431808).

Almost surely, 2^663011321 is an apocalyptic number.

It is an amenable number.

663011321 is a deficient number, since it is larger than the sum of its proper divisors (94715911).

663011321 is an equidigital number, since it uses as much as digits as its factorization.

663011321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94715910.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 663011321 is about 25749.0062138328. The cubic root of 663011321 is about 871.9809184340.

Adding to 663011321 its reverse (123110366), we get a palindrome (786121687).

The spelling of 663011321 in words is "six hundred sixty-three million, eleven thousand, three hundred twenty-one".