20540455217 has 2 divisors, whose sum is σ = 20540455218. Its totient is φ = 20540455216.

The previous prime is 20540455183. The next prime is 20540455223. The reversal of 20540455217 is 71255404502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20440134961 + 100320256 = 142969^2 + 10016^2 .

It is a cyclic number.

It is not a de Polignac number, because 20540455217 - 2²⁶ = 20473346353 is a prime.

It is not a weakly prime, because it can be changed into another prime (20540455297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10270227608 + 10270227609.

It is an arithmetic number, because the mean of its divisors is an integer number (10270227609).

Almost surely, 2^20540455217 is an apocalyptic number.

It is an amenable number.

20540455217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20540455217 is an equidigital number, since it uses as much as digits as its factorization.

20540455217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56000, while the sum is 35.

Adding to 20540455217 its reverse (71255404502), we get a palindrome (91795859719).

The spelling of 20540455217 in words is "twenty billion, five hundred forty million, four hundred fifty-five thousand, two hundred seventeen".