66113997617 has 2 divisors, whose sum is σ = 66113997618. Its totient is φ = 66113997616.

The previous prime is 66113997581. The next prime is 66113997619. The reversal of 66113997617 is 71679931166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44598681856 + 21515315761 = 211184^2 + 146681^2 .

It is a cyclic number.

It is not a de Polignac number, because 66113997617 - 2¹² = 66113993521 is a prime.

Together with 66113997619, 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 (66113997619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33056998808 + 33056998809.

It is an arithmetic number, because the mean of its divisors is an integer number (33056998809).

Almost surely, 2^66113997617 is an apocalyptic number.

It is an amenable number.

66113997617 is a deficient number, since it is larger than the sum of its proper divisors (1).

66113997617 is an equidigital number, since it uses as much as digits as its factorization.

66113997617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2571912, while the sum is 56.

The spelling of 66113997617 in words is "sixty-six billion, one hundred thirteen million, nine hundred ninety-seven thousand, six hundred seventeen".