1320320525521 has 2 divisors, whose sum is σ = 1320320525522. Its totient is φ = 1320320525520.

The previous prime is 1320320525501. The next prime is 1320320525561. The reversal of 1320320525521 is 1255250230231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 971724749121 + 348595776400 = 985761^2 + 590420^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320320525521 - 2⁹ = 1320320525009 is a prime.

It is a super-2 number, since 2×1320320525521² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1320320525501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660160262760 + 660160262761.

It is an arithmetic number, because the mean of its divisors is an integer number (660160262761).

Almost surely, 2^{1320320525521} is an apocalyptic number.

It is an amenable number.

1320320525521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320320525521 is an equidigital number, since it uses as much as digits as its factorization.

1320320525521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 1320320525521 its reverse (1255250230231), we get a palindrome (2575570755752).

The spelling of 1320320525521 in words is "one trillion, three hundred twenty billion, three hundred twenty million, five hundred twenty-five thousand, five hundred twenty-one".