1331221213 has 4 divisors (see below), whose sum is σ = 1521395680. Its totient is φ = 1141046748.

The previous prime is 1331221121. The next prime is 1331221231. The reversal of 1331221213 is 3121221331.

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 1331221213 - 2²⁵ = 1297666781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331221273) 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, 95087223 + ... + 95087236.

It is an arithmetic number, because the mean of its divisors is an integer number (380348920).

Almost surely, 2^1331221213 is an apocalyptic number.

It is an amenable number.

1331221213 is a deficient number, since it is larger than the sum of its proper divisors (190174467).

1331221213 is an equidigital number, since it uses as much as digits as its factorization.

1331221213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190174466.

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

The square root of 1331221213 is about 36485.9043056356. The cubic root of 1331221213 is about 1100.0609368446.

Adding to 1331221213 its reverse (3121221331), we get a palindrome (4452442544).

The spelling of 1331221213 in words is "one billion, three hundred thirty-one million, two hundred twenty-one thousand, two hundred thirteen".