2011220999981 has 2 divisors, whose sum is σ = 2011220999982. Its totient is φ = 2011220999980.

The previous prime is 2011220999947. The next prime is 2011220999993. The reversal of 2011220999981 is 1899990221102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1470604909225 + 540616090756 = 1212685^2 + 735266^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2011220999981 is a prime.

It is a super-2 number, since 2×2011220999981² (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 (2011220999681) 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, 1005610499990 + 1005610499991.

It is an arithmetic number, because the mean of its divisors is an integer number (1005610499991).

Almost surely, 2^{2011220999981} is an apocalyptic number.

It is an amenable number.

2011220999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011220999981 is an equidigital number, since it uses as much as digits as its factorization.

2011220999981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 53.

The spelling of 2011220999981 in words is "two trillion, eleven billion, two hundred twenty million, nine hundred ninety-nine thousand, nine hundred eighty-one".