1211102020981 has 2 divisors, whose sum is σ = 1211102020982. Its totient is φ = 1211102020980.

The previous prime is 1211102020889. The next prime is 1211102021009. The reversal of 1211102020981 is 1890202011121.

It is an a-pointer prime, because the next prime (1211102021009) can be obtained adding 1211102020981 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1148005102500 + 63096918481 = 1071450^2 + 251191^2 .

It is an emirp because it is prime and its reverse (1890202011121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211102020981 - 2¹⁷ = 1211101889909 is a prime.

It is a super-2 number, since 2×1211102020981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211102020181) 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, 605551010490 + 605551010491.

It is an arithmetic number, because the mean of its divisors is an integer number (605551010491).

Almost surely, 2^{1211102020981} is an apocalyptic number.

It is an amenable number.

1211102020981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211102020981 is an equidigital number, since it uses as much as digits as its factorization.

1211102020981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 28.

The spelling of 1211102020981 in words is "one trillion, two hundred eleven billion, one hundred two million, twenty thousand, nine hundred eighty-one".