666849229639 has 2 divisors, whose sum is σ = 666849229640. Its totient is φ = 666849229638.

The previous prime is 666849229621. The next prime is 666849229691. The reversal of 666849229639 is 936922948666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666849229639 - 2¹¹ = 666849227591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666849229619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333424614819 + 333424614820.

It is an arithmetic number, because the mean of its divisors is an integer number (333424614820).

Almost surely, 2^666849229639 is an apocalyptic number.

666849229639 is a deficient number, since it is larger than the sum of its proper divisors (1).

666849229639 is an equidigital number, since it uses as much as digits as its factorization.

666849229639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362797056, while the sum is 70.

The spelling of 666849229639 in words is "six hundred sixty-six billion, eight hundred forty-nine million, two hundred twenty-nine thousand, six hundred thirty-nine".