646405659389951 has 2 divisors, whose sum is σ = 646405659389952. Its totient is φ = 646405659389950.

The previous prime is 646405659389947. The next prime is 646405659389977. The reversal of 646405659389951 is 159983956504646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646405659389951 - 2² = 646405659389947 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646405659389851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323202829694975 + 323202829694976.

It is an arithmetic number, because the mean of its divisors is an integer number (323202829694976).

Almost surely, 2^{646405659389951} is an apocalyptic number.

646405659389951 is a deficient number, since it is larger than the sum of its proper divisors (1).

646405659389951 is an equidigital number, since it uses as much as digits as its factorization.

646405659389951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7558272000, while the sum is 80.

The spelling of 646405659389951 in words is "six hundred forty-six trillion, four hundred five billion, six hundred fifty-nine million, three hundred eighty-nine thousand, nine hundred fifty-one".