20212111181 has 2 divisors, whose sum is σ = 20212111182. Its totient is φ = 20212111180.

The previous prime is 20212111169. The next prime is 20212111187. The reversal of 20212111181 is 18111121202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16304736100 + 3907375081 = 127690^2 + 62509^2 .

It is a cyclic number.

It is not a de Polignac number, because 20212111181 - 2¹⁸ = 20211849037 is a prime.

It is a super-2 number, since 2×20212111181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20212111187) 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, 10106055590 + 10106055591.

It is an arithmetic number, because the mean of its divisors is an integer number (10106055591).

Almost surely, 2^20212111181 is an apocalyptic number.

It is an amenable number.

20212111181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20212111181 is an equidigital number, since it uses as much as digits as its factorization.

20212111181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 20212111181 its reverse (18111121202), we get a palindrome (38323232383).

The spelling of 20212111181 in words is "twenty billion, two hundred twelve million, one hundred eleven thousand, one hundred eighty-one".