1311102020021 has 2 divisors, whose sum is σ = 1311102020022. Its totient is φ = 1311102020020.

The previous prime is 1311102020017. The next prime is 1311102020027. The reversal of 1311102020021 is 1200202011131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1293701508100 + 17400511921 = 1137410^2 + 131911^2 .

It is an emirp because it is prime and its reverse (1200202011131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1311102020021 - 2² = 1311102020017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1311102019978 and 1311102020005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311102020027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655551010010 + 655551010011.

It is an arithmetic number, because the mean of its divisors is an integer number (655551010011).

Almost surely, 2^{1311102020021} is an apocalyptic number.

It is an amenable number.

1311102020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311102020021 is an equidigital number, since it uses as much as digits as its factorization.

1311102020021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 1311102020021 its reverse (1200202011131), we get a palindrome (2511304031152).

The spelling of 1311102020021 in words is "one trillion, three hundred eleven billion, one hundred two million, twenty thousand, twenty-one".