12171112181 has 2 divisors, whose sum is σ = 12171112182. Its totient is φ = 12171112180.

The previous prime is 12171112157. The next prime is 12171112211. The reversal of 12171112181 is 18121117121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6215903281 + 5955208900 = 78841^2 + 77170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12171112181 is a prime.

It is a super-2 number, since 2×12171112181² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12171112181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12171112081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6085556090 + 6085556091.

It is an arithmetic number, because the mean of its divisors is an integer number (6085556091).

Almost surely, 2^12171112181 is an apocalyptic number.

It is an amenable number.

12171112181 is a deficient number, since it is larger than the sum of its proper divisors (1).

12171112181 is an equidigital number, since it uses as much as digits as its factorization.

12171112181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 224, while the sum is 26.

The spelling of 12171112181 in words is "twelve billion, one hundred seventy-one million, one hundred twelve thousand, one hundred eighty-one".