21523118102117 has 2 divisors, whose sum is σ = 21523118102118. Its totient is φ = 21523118102116.

The previous prime is 21523118102111. The next prime is 21523118102197. The reversal of 21523118102117 is 71120181132512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15388351994401 + 6134766107716 = 3922799^2 + 2476846^2 .

It is a cyclic number.

It is not a de Polignac number, because 21523118102117 - 2²⁰ = 21523117053541 is a prime.

It is a super-3 number, since 3×21523118102117³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21523118102111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761559051058 + 10761559051059.

It is an arithmetic number, because the mean of its divisors is an integer number (10761559051059).

Almost surely, 2^{21523118102117} is an apocalyptic number.

It is an amenable number.

21523118102117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21523118102117 is an equidigital number, since it uses as much as digits as its factorization.

21523118102117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 35.

Adding to 21523118102117 its reverse (71120181132512), we get a palindrome (92643299234629).

The spelling of 21523118102117 in words is "twenty-one trillion, five hundred twenty-three billion, one hundred eighteen million, one hundred two thousand, one hundred seventeen".