21113524566217 has 2 divisors, whose sum is σ = 21113524566218. Its totient is φ = 21113524566216.

The previous prime is 21113524566193. The next prime is 21113524566229. The reversal of 21113524566217 is 71266542531112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20216003280841 + 897521285376 = 4496221^2 + 947376^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113524566217 - 2⁷ = 21113524566089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21113524566317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556762283108 + 10556762283109.

It is an arithmetic number, because the mean of its divisors is an integer number (10556762283109).

Almost surely, 2^{21113524566217} is an apocalyptic number.

It is an amenable number.

21113524566217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113524566217 is an equidigital number, since it uses as much as digits as its factorization.

21113524566217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 604800, while the sum is 46.

The spelling of 21113524566217 in words is "twenty-one trillion, one hundred thirteen billion, five hundred twenty-four million, five hundred sixty-six thousand, two hundred seventeen".