1321320121313 has 4 divisors (see below), whose sum is σ = 1321339801860. Its totient is φ = 1321300440768.

The previous prime is 1321320121309. The next prime is 1321320121327. The reversal of 1321320121313 is 3131210231231.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 174596115409 + 1146724005904 = 417847^2 + 1070852^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321320121313 - 2² = 1321320121309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321320121333) 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, 9739220 + ... + 9873957.

It is an arithmetic number, because the mean of its divisors is an integer number (330334950465).

Almost surely, 2^{1321320121313} is an apocalyptic number.

It is an amenable number.

1321320121313 is a deficient number, since it is larger than the sum of its proper divisors (19680547).

1321320121313 is an equidigital number, since it uses as much as digits as its factorization.

1321320121313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19680546.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 1321320121313 its reverse (3131210231231), we get a palindrome (4452530352544).

The spelling of 1321320121313 in words is "one trillion, three hundred twenty-one billion, three hundred twenty million, one hundred twenty-one thousand, three hundred thirteen".