66531317971 has 2 divisors, whose sum is σ = 66531317972. Its totient is φ = 66531317970.

The previous prime is 66531317939. The next prime is 66531317981. The reversal of 66531317971 is 17971313566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66531317971 - 2⁵ = 66531317939 is a prime.

It is not a weakly prime, because it can be changed into another prime (66531317981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33265658985 + 33265658986.

It is an arithmetic number, because the mean of its divisors is an integer number (33265658986).

Almost surely, 2^66531317971 is an apocalyptic number.

66531317971 is a deficient number, since it is larger than the sum of its proper divisors (1).

66531317971 is an equidigital number, since it uses as much as digits as its factorization.

66531317971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 714420, while the sum is 49.

The spelling of 66531317971 in words is "sixty-six billion, five hundred thirty-one million, three hundred seventeen thousand, nine hundred seventy-one".