1321020313021 has 2 divisors, whose sum is σ = 1321020313022. Its totient is φ = 1321020313020.

The previous prime is 1321020313013. The next prime is 1321020313073. The reversal of 1321020313021 is 1203130201231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1217908680921 + 103111632100 = 1103589^2 + 321110^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321020313021 - 2³ = 1321020313013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321020313021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321020313321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660510156510 + 660510156511.

It is an arithmetic number, because the mean of its divisors is an integer number (660510156511).

Almost surely, 2^{1321020313021} is an apocalyptic number.

It is an amenable number.

1321020313021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321020313021 is an equidigital number, since it uses as much as digits as its factorization.

1321020313021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 1321020313021 its reverse (1203130201231), we get a palindrome (2524150514252).

The spelling of 1321020313021 in words is "one trillion, three hundred twenty-one billion, twenty million, three hundred thirteen thousand, twenty-one".