21663226230517 has 2 divisors, whose sum is σ = 21663226230518. Its totient is φ = 21663226230516.

The previous prime is 21663226230493. The next prime is 21663226230523. The reversal of 21663226230517 is 71503262236612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20422499803876 + 1240726426641 = 4519126^2 + 1113879^2 .

It is a cyclic number.

It is not a de Polignac number, because 21663226230517 - 2²⁷ = 21663092012789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21663226230577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10831613115258 + 10831613115259.

It is an arithmetic number, because the mean of its divisors is an integer number (10831613115259).

Almost surely, 2^{21663226230517} is an apocalyptic number.

It is an amenable number.

21663226230517 is a deficient number, since it is larger than the sum of its proper divisors (1).

21663226230517 is an equidigital number, since it uses as much as digits as its factorization.

21663226230517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1088640, while the sum is 46.

The spelling of 21663226230517 in words is "twenty-one trillion, six hundred sixty-three billion, two hundred twenty-six million, two hundred thirty thousand, five hundred seventeen".