1313321211221 has 4 divisors (see below), whose sum is σ = 1370422133472. Its totient is φ = 1256220288972.

The previous prime is 1313321211203. The next prime is 1313321211239. The reversal of 1313321211221 is 1221121233131.

It is a happy number.

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 an interprime number because it is at equal distance from previous prime (1313321211203) and next prime (1313321211239).

It is a cyclic number.

It is not a de Polignac number, because 1313321211221 - 2¹⁰ = 1313321210197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 57100922227 = 1313321211221 / (1 + 3 + 1 + 3 + 3 + 2 + 1 + 2 + 1 + 1 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313321211271) 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, 28550461091 + ... + 28550461136.

It is an arithmetic number, because the mean of its divisors is an integer number (342605533368).

Almost surely, 2^{1313321211221} is an apocalyptic number.

It is an amenable number.

1313321211221 is a deficient number, since it is larger than the sum of its proper divisors (57100922251).

1313321211221 is an equidigital number, since it uses as much as digits as its factorization.

1313321211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57100922250.

The product of its digits is 432, while the sum is 23.

Adding to 1313321211221 its reverse (1221121233131), we get a palindrome (2534442444352).

The spelling of 1313321211221 in words is "one trillion, three hundred thirteen billion, three hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".