11000020019981 has 2 divisors, whose sum is σ = 11000020019982. Its totient is φ = 11000020019980.

The previous prime is 11000020019971. The next prime is 11000020020019. The reversal of 11000020019981 is 18991002000011.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10992480571081 + 7539448900 = 3315491^2 + 86830^2 .

It is an emirp because it is prime and its reverse (18991002000011) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11000020019981 - 2⁶ = 11000020019917 is a prime.

It is a super-2 number, since 2×11000020019981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11000020019971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5500010009990 + 5500010009991.

It is an arithmetic number, because the mean of its divisors is an integer number (5500010009991).

Almost surely, 2^{11000020019981} is an apocalyptic number.

It is an amenable number.

11000020019981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11000020019981 is an equidigital number, since it uses as much as digits as its factorization.

11000020019981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 32.

Adding to 11000020019981 its reverse (18991002000011), we get a palindrome (29991022019992).

The spelling of 11000020019981 in words is "eleven trillion, twenty million, nineteen thousand, nine hundred eighty-one".