66851594647 has 2 divisors, whose sum is σ = 66851594648. Its totient is φ = 66851594646.

The previous prime is 66851594533. The next prime is 66851594651. The reversal of 66851594647 is 74649515866.

66851594647 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66851594647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66851594347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33425797323 + 33425797324.

It is an arithmetic number, because the mean of its divisors is an integer number (33425797324).

Almost surely, 2^66851594647 is an apocalyptic number.

66851594647 is a deficient number, since it is larger than the sum of its proper divisors (1).

66851594647 is an equidigital number, since it uses as much as digits as its factorization.

66851594647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43545600, while the sum is 61.

The spelling of 66851594647 in words is "sixty-six billion, eight hundred fifty-one million, five hundred ninety-four thousand, six hundred forty-seven".