66686855071 has 2 divisors, whose sum is σ = 66686855072. Its totient is φ = 66686855070.

The previous prime is 66686855023. The next prime is 66686855107. The reversal of 66686855071 is 17055868666.

Together with next prime (66686855107) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66686855071 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66686854997 and 66686855015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66686835071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33343427535 + 33343427536.

It is an arithmetic number, because the mean of its divisors is an integer number (33343427536).

Almost surely, 2^66686855071 is an apocalyptic number.

66686855071 is a deficient number, since it is larger than the sum of its proper divisors (1).

66686855071 is an equidigital number, since it uses as much as digits as its factorization.

66686855071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14515200, while the sum is 58.

The spelling of 66686855071 in words is "sixty-six billion, six hundred eighty-six million, eight hundred fifty-five thousand, seventy-one".