1321320211221 has 4 divisors (see below), whose sum is σ = 1761760281632. Its totient is φ = 880880140812.

The previous prime is 1321320211157. The next prime is 1321320211249. The reversal of 1321320211221 is 1221120231231.

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 not a de Polignac number, because 1321320211221 - 2⁶ = 1321320211157 is a prime.

It is a super-2 number, since 2×1321320211221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321320212221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220220035201 + ... + 220220035206.

It is an arithmetic number, because the mean of its divisors is an integer number (440440070408).

Almost surely, 2^{1321320211221} is an apocalyptic number.

It is an amenable number.

1321320211221 is a deficient number, since it is larger than the sum of its proper divisors (440440070411).

1321320211221 is an equidigital number, since it uses as much as digits as its factorization.

1321320211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440440070410.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 1321320211221 its reverse (1221120231231), we get a palindrome (2542440442452).

The spelling of 1321320211221 in words is "one trillion, three hundred twenty-one billion, three hundred twenty million, two hundred eleven thousand, two hundred twenty-one".