1321231213 has 4 divisors (see below), whose sum is σ = 1366790940. Its totient is φ = 1275671488.

The previous prime is 1321231207. The next prime is 1321231217. The reversal of 1321231213 is 3121321231.

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 1043742249 + 277488964 = 32307^2 + 16658^2 .

It is not a de Polignac number, because 1321231213 - 2⁵ = 1321231181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321231217) 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, 22779820 + ... + 22779877.

It is an arithmetic number, because the mean of its divisors is an integer number (341697735).

Almost surely, 2^1321231213 is an apocalyptic number.

It is an amenable number.

1321231213 is a deficient number, since it is larger than the sum of its proper divisors (45559727).

1321231213 is an equidigital number, since it uses as much as digits as its factorization.

1321231213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45559726.

The product of its digits is 216, while the sum is 19.

The square root of 1321231213 is about 36348.7443111863. The cubic root of 1321231213 is about 1097.3022633470.

Adding to 1321231213 its reverse (3121321231), we get a palindrome (4442552444).

The spelling of 1321231213 in words is "one billion, three hundred twenty-one million, two hundred thirty-one thousand, two hundred thirteen".