12456717522421 has 2 divisors, whose sum is σ = 12456717522422. Its totient is φ = 12456717522420.

The previous prime is 12456717522419. The next prime is 12456717522467. The reversal of 12456717522421 is 12422571765421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6468120562500 + 5988596959921 = 2543250^2 + 2447161^2 .

It is a cyclic number.

It is not a de Polignac number, because 12456717522421 - 2¹ = 12456717522419 is a prime.

It is a super-2 number, since 2×12456717522421² (a number of 27 digits) contains 22 as substring.

Together with 12456717522419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12456717522721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6228358761210 + 6228358761211.

It is an arithmetic number, because the mean of its divisors is an integer number (6228358761211).

Almost surely, 2^{12456717522421} is an apocalyptic number.

It is an amenable number.

12456717522421 is a deficient number, since it is larger than the sum of its proper divisors (1).

12456717522421 is an equidigital number, since it uses as much as digits as its factorization.

12456717522421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1881600, while the sum is 49.

The spelling of 12456717522421 in words is "twelve trillion, four hundred fifty-six billion, seven hundred seventeen million, five hundred twenty-two thousand, four hundred twenty-one".