666616113425321 has 2 divisors, whose sum is σ = 666616113425322. Its totient is φ = 666616113425320.

The previous prime is 666616113425179. The next prime is 666616113425323. The reversal of 666616113425321 is 123524311616666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 575097425853721 + 91518687571600 = 23981189^2 + 9566540^2 .

It is a cyclic number.

It is not a de Polignac number, because 666616113425321 - 2³⁰ = 666615039683497 is a prime.

Together with 666616113425323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666616113425323) 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, 333308056712660 + 333308056712661.

It is an arithmetic number, because the mean of its divisors is an integer number (333308056712661).

Almost surely, 2^{666616113425321} is an apocalyptic number.

It is an amenable number.

666616113425321 is a deficient number, since it is larger than the sum of its proper divisors (1).

666616113425321 is an equidigital number, since it uses as much as digits as its factorization.

666616113425321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5598720, while the sum is 53.

The spelling of 666616113425321 in words is "six hundred sixty-six trillion, six hundred sixteen billion, one hundred thirteen million, four hundred twenty-five thousand, three hundred twenty-one".