20126256127181 has 2 divisors, whose sum is σ = 20126256127182. Its totient is φ = 20126256127180.

The previous prime is 20126256127177. The next prime is 20126256127183. The reversal of 20126256127181 is 18172165262102.

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., 15952954633225 + 4173301493956 = 3994115^2 + 2042866^2 .

It is a cyclic number.

It is not a de Polignac number, because 20126256127181 - 2² = 20126256127177 is a prime.

It is a super-2 number, since 2×20126256127181² (a number of 27 digits) contains 22 as substring.

Together with 20126256127183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20126256127183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10063128063590 + 10063128063591.

It is an arithmetic number, because the mean of its divisors is an integer number (10063128063591).

Almost surely, 2^{20126256127181} is an apocalyptic number.

It is an amenable number.

20126256127181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20126256127181 is an equidigital number, since it uses as much as digits as its factorization.

20126256127181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 20126256127181 in words is "twenty trillion, one hundred twenty-six billion, two hundred fifty-six million, one hundred twenty-seven thousand, one hundred eighty-one".