1321220213 has 4 divisors (see below), whose sum is σ = 1326244128. Its totient is φ = 1316196300.

The previous prime is 1321220207. The next prime is 1321220227. The reversal of 1321220213 is 3120221231.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3120221231 = 3877 ⋅804803.

It is a cyclic number.

It is not a de Polignac number, because 1321220213 - 2²⁰ = 1320171637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321220191 and 1321220200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321220513) 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, 2511563 + ... + 2512088.

It is an arithmetic number, because the mean of its divisors is an integer number (331561032).

Almost surely, 2^1321220213 is an apocalyptic number.

It is an amenable number.

1321220213 is a deficient number, since it is larger than the sum of its proper divisors (5023915).

1321220213 is an equidigital number, since it uses as much as digits as its factorization.

1321220213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5023914.

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

The square root of 1321220213 is about 36348.5929989044. The cubic root of 1321220213 is about 1097.2992181171.

Adding to 1321220213 its reverse (3120221231), we get a palindrome (4441441444).

The spelling of 1321220213 in words is "one billion, three hundred twenty-one million, two hundred twenty thousand, two hundred thirteen".