668820885251 has 2 divisors, whose sum is σ = 668820885252. Its totient is φ = 668820885250.

The previous prime is 668820885203. The next prime is 668820885269. The reversal of 668820885251 is 152588028866.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668820885251 is a prime.

It is not a weakly prime, because it can be changed into another prime (668820882251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334410442625 + 334410442626.

It is an arithmetic number, because the mean of its divisors is an integer number (334410442626).

Almost surely, 2^668820885251 is an apocalyptic number.

668820885251 is a deficient number, since it is larger than the sum of its proper divisors (1).

668820885251 is an equidigital number, since it uses as much as digits as its factorization.

668820885251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14745600, while the sum is 59.

The spelling of 668820885251 in words is "six hundred sixty-eight billion, eight hundred twenty million, eight hundred eighty-five thousand, two hundred fifty-one".