20012220209981 has 2 divisors, whose sum is σ = 20012220209982. Its totient is φ = 20012220209980.

The previous prime is 20012220209959. The next prime is 20012220210163. The reversal of 20012220209981 is 18990202221002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13408522915225 + 6603697294756 = 3661765^2 + 2569766^2 .

It is a cyclic number.

It is not a de Polignac number, because 20012220209981 - 2¹⁰ = 20012220208957 is a prime.

It is a super-2 number, since 2×20012220209981² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20012220209911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006110104990 + 10006110104991.

It is an arithmetic number, because the mean of its divisors is an integer number (10006110104991).

Almost surely, 2^{20012220209981} is an apocalyptic number.

It is an amenable number.

20012220209981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20012220209981 is an equidigital number, since it uses as much as digits as its factorization.

20012220209981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 38.

The spelling of 20012220209981 in words is "twenty trillion, twelve billion, two hundred twenty million, two hundred nine thousand, nine hundred eighty-one".