20123211181 has 2 divisors, whose sum is σ = 20123211182. Its totient is φ = 20123211180.

The previous prime is 20123211103. The next prime is 20123211187. The reversal of 20123211181 is 18111232102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10492929225 + 9630281956 = 102435^2 + 98134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20123211181 is a prime.

It is a super-2 number, since 2×20123211181² (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 (20123211187) 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, 10061605590 + 10061605591.

It is an arithmetic number, because the mean of its divisors is an integer number (10061605591).

Almost surely, 2^20123211181 is an apocalyptic number.

It is an amenable number.

20123211181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20123211181 is an equidigital number, since it uses as much as digits as its factorization.

20123211181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 22.

Adding to 20123211181 its reverse (18111232102), we get a palindrome (38234443283).

The spelling of 20123211181 in words is "twenty billion, one hundred twenty-three million, two hundred eleven thousand, one hundred eighty-one".