1213322321 has 4 divisors (see below), whose sum is σ = 1213402212. Its totient is φ = 1213242432.

The previous prime is 1213322293. The next prime is 1213322333. The reversal of 1213322321 is 1232233121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 680635921 + 532686400 = 26089^2 + 23080^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1213322321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1213322293 and 1213322302.

It is not an unprimeable number, because it can be changed into a prime (1213322371) 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, 9356 + ... + 50141.

It is an arithmetic number, because the mean of its divisors is an integer number (303350553).

Almost surely, 2^1213322321 is an apocalyptic number.

It is an amenable number.

1213322321 is a deficient number, since it is larger than the sum of its proper divisors (79891).

1213322321 is an equidigital number, since it uses as much as digits as its factorization.

1213322321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79890.

The product of its digits is 432, while the sum is 20.

The square root of 1213322321 is about 34832.7765330299. The cubic root of 1213322321 is about 1066.5766272414.

Adding to 1213322321 its reverse (1232233121), we get a palindrome (2445555442).

The spelling of 1213322321 in words is "one billion, two hundred thirteen million, three hundred twenty-two thousand, three hundred twenty-one".