1320202306561 has 2 divisors, whose sum is σ = 1320202306562. Its totient is φ = 1320202306560.

The previous prime is 1320202306523. The next prime is 1320202306567. The reversal of 1320202306561 is 1656032020231.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 687929242225 + 632273064336 = 829415^2 + 795156^2 .

It is an emirp because it is prime and its reverse (1656032020231) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320202306561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1320202306567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660101153280 + 660101153281.

It is an arithmetic number, because the mean of its divisors is an integer number (660101153281).

Almost surely, 2^{1320202306561} is an apocalyptic number.

It is an amenable number.

1320202306561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320202306561 is an equidigital number, since it uses as much as digits as its factorization.

1320202306561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

Adding to 1320202306561 its reverse (1656032020231), we get a palindrome (2976234326792).

The spelling of 1320202306561 in words is "one trillion, three hundred twenty billion, two hundred two million, three hundred six thousand, five hundred sixty-one".