20117504772181 has 2 divisors, whose sum is σ = 20117504772182. Its totient is φ = 20117504772180.

The previous prime is 20117504772097. The next prime is 20117504772191. The reversal of 20117504772181 is 18127740571102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16516429249681 + 3601075522500 = 4064041^2 + 1897650^2 .

It is a cyclic number.

It is not a de Polignac number, because 20117504772181 - 2⁹ = 20117504771669 is a prime.

It is a super-2 number, since 2×20117504772181² (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 (20117504772191) 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, 10058752386090 + 10058752386091.

It is an arithmetic number, because the mean of its divisors is an integer number (10058752386091).

Almost surely, 2^{20117504772181} is an apocalyptic number.

It is an amenable number.

20117504772181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20117504772181 is an equidigital number, since it uses as much as digits as its factorization.

20117504772181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 219520, while the sum is 46.

The spelling of 20117504772181 in words is "twenty trillion, one hundred seventeen billion, five hundred four million, seven hundred seventy-two thousand, one hundred eighty-one".