1213222321 has 4 divisors (see below), whose sum is σ = 1213851892. Its totient is φ = 1212592752.

The previous prime is 1213222313. The next prime is 1213222363. The reversal of 1213222321 is 1232223121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 918756721 + 294465600 = 30311^2 + 17160^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213222321 - 2³ = 1213222313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213222721) 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, 311886 + ... + 315751.

It is an arithmetic number, because the mean of its divisors is an integer number (303462973).

Almost surely, 2^1213222321 is an apocalyptic number.

It is an amenable number.

1213222321 is a deficient number, since it is larger than the sum of its proper divisors (629571).

1213222321 is an equidigital number, since it uses as much as digits as its factorization.

1213222321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629570.

The product of its digits is 288, while the sum is 19.

The square root of 1213222321 is about 34831.3410738088. The cubic root of 1213222321 is about 1066.5473246147.

Adding to 1213222321 its reverse (1232223121), we get a palindrome (2445445442).

It can be divided in two parts, 12132 and 22321, that added together give a triangular number (34453 = T₂₆₂).

The spelling of 1213222321 in words is "one billion, two hundred thirteen million, two hundred twenty-two thousand, three hundred twenty-one".