20011111198181 has 2 divisors, whose sum is σ = 20011111198182. Its totient is φ = 20011111198180.

The previous prime is 20011111198123. The next prime is 20011111198223. The reversal of 20011111198181 is 18189111111002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19651400340100 + 359710858081 = 4432990^2 + 599759^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011111198181 - 2³⁴ = 19993931328997 is a prime.

It is a super-2 number, since 2×20011111198181² (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 (20011111198381) 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, 10005555599090 + 10005555599091.

It is an arithmetic number, because the mean of its divisors is an integer number (10005555599091).

Almost surely, 2^{20011111198181} is an apocalyptic number.

It is an amenable number.

20011111198181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011111198181 is an equidigital number, since it uses as much as digits as its factorization.

20011111198181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 35.

The spelling of 20011111198181 in words is "twenty trillion, eleven billion, one hundred eleven million, one hundred ninety-eight thousand, one hundred eighty-one".