1331320331221 has 4 divisors (see below), whose sum is σ = 1331600554944. Its totient is φ = 1331040107500.

The previous prime is 1331320331219. The next prime is 1331320331233. The reversal of 1331320331221 is 1221330231331.

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 1331320331221 - 2¹ = 1331320331219 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 (1331320334221) 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, 140104735 + ... + 140114236.

It is an arithmetic number, because the mean of its divisors is an integer number (332900138736).

Almost surely, 2^{1331320331221} is an apocalyptic number.

It is an amenable number.

1331320331221 is a deficient number, since it is larger than the sum of its proper divisors (280223723).

1331320331221 is an equidigital number, since it uses as much as digits as its factorization.

1331320331221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280223722.

The product of its (nonzero) digits is 1944, while the sum is 25.

Adding to 1331320331221 its reverse (1221330231331), we get a palindrome (2552650562552).

The spelling of 1331320331221 in words is "one trillion, three hundred thirty-one billion, three hundred twenty million, three hundred thirty-one thousand, two hundred twenty-one".