630021221 has 4 divisors (see below), whose sum is σ = 657413472. Its totient is φ = 602628972.

The previous prime is 630021187. The next prime is 630021257. The reversal of 630021221 is 122120036.

630021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 630021221 - 2⁶ = 630021157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 630021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (630021281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13696091 + ... + 13696136.

It is an arithmetic number, because the mean of its divisors is an integer number (164353368).

Almost surely, 2^630021221 is an apocalyptic number.

It is an amenable number.

630021221 is a deficient number, since it is larger than the sum of its proper divisors (27392251).

630021221 is a wasteful number, since it uses less digits than its factorization.

630021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27392250.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 630021221 is about 25100.2235249011. The cubic root of 630021221 is about 857.2715134960.

Adding to 630021221 its reverse (122120036), we get a palindrome (752141257).

The spelling of 630021221 in words is "six hundred thirty million, twenty-one thousand, two hundred twenty-one".