668051256871 has 2 divisors, whose sum is σ = 668051256872. Its totient is φ = 668051256870.

The previous prime is 668051256853. The next prime is 668051256893. The reversal of 668051256871 is 178652150866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668051256871 - 2²¹ = 668049159719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668051256811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334025628435 + 334025628436.

It is an arithmetic number, because the mean of its divisors is an integer number (334025628436).

Almost surely, 2^668051256871 is an apocalyptic number.

668051256871 is a deficient number, since it is larger than the sum of its proper divisors (1).

668051256871 is an equidigital number, since it uses as much as digits as its factorization.

668051256871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4838400, while the sum is 55.

The spelling of 668051256871 in words is "six hundred sixty-eight billion, fifty-one million, two hundred fifty-six thousand, eight hundred seventy-one".