666071864639 has 2 divisors, whose sum is σ = 666071864640. Its totient is φ = 666071864638.

The previous prime is 666071864533. The next prime is 666071864677. The reversal of 666071864639 is 936468170666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666071864639 - 2⁸ = 666071864383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666071860639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333035932319 + 333035932320.

It is an arithmetic number, because the mean of its divisors is an integer number (333035932320).

Almost surely, 2^666071864639 is an apocalyptic number.

666071864639 is a deficient number, since it is larger than the sum of its proper divisors (1).

666071864639 is an equidigital number, since it uses as much as digits as its factorization.

666071864639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47029248, while the sum is 62.

The spelling of 666071864639 in words is "six hundred sixty-six billion, seventy-one million, eight hundred sixty-four thousand, six hundred thirty-nine".