21660563124127 has 2 divisors, whose sum is σ = 21660563124128. Its totient is φ = 21660563124126.

The previous prime is 21660563124121. The next prime is 21660563124173. The reversal of 21660563124127 is 72142136506612.

It is an a-pointer prime, because the next prime (21660563124173) can be obtained adding 21660563124127 to its sum of digits (46).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21660563124127 - 2³⁹ = 21110807310239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21660563124121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830281562063 + 10830281562064.

It is an arithmetic number, because the mean of its divisors is an integer number (10830281562064).

Almost surely, 2^{21660563124127} is an apocalyptic number.

21660563124127 is a deficient number, since it is larger than the sum of its proper divisors (1).

21660563124127 is an equidigital number, since it uses as much as digits as its factorization.

21660563124127 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 46.

The spelling of 21660563124127 in words is "twenty-one trillion, six hundred sixty billion, five hundred sixty-three million, one hundred twenty-four thousand, one hundred twenty-seven".