1305320521321 has 4 divisors (see below), whose sum is σ = 1347427634944. Its totient is φ = 1263213407700.

The previous prime is 1305320521313. The next prime is 1305320521423. The reversal of 1305320521321 is 1231250235031.

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 1305320521321 - 2³ = 1305320521313 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1305320521321.

It is not an unprimeable number, because it can be changed into a prime (1305320528321) 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, 21053556765 + ... + 21053556826.

It is an arithmetic number, because the mean of its divisors is an integer number (336856908736).

Almost surely, 2^{1305320521321} is an apocalyptic number.

It is an amenable number.

1305320521321 is a deficient number, since it is larger than the sum of its proper divisors (42107113623).

1305320521321 is an equidigital number, since it uses as much as digits as its factorization.

1305320521321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42107113622.

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 1305320521321 its reverse (1231250235031), we get a palindrome (2536570756352).

The spelling of 1305320521321 in words is "one trillion, three hundred five billion, three hundred twenty million, five hundred twenty-one thousand, three hundred twenty-one".