643464351651 has 64 divisors (see below), whose sum is σ = 994865633280. Its totient is φ = 366179304960.

The previous prime is 643464351611. The next prime is 643464351671. The reversal of 643464351651 is 156153464346.

It is a happy number.

It is not a de Polignac number, because 643464351651 - 2¹⁸ = 643464089507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643464351651.

It is not an unprimeable number, because it can be changed into a prime (643464351601) 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 in 63 ways as a sum of consecutive naturals, for example, 124530870 + ... + 124536036.

It is an arithmetic number, because the mean of its divisors is an integer number (15544775520).

Almost surely, 2^643464351651 is an apocalyptic number.

643464351651 is a deficient number, since it is larger than the sum of its proper divisors (351401281629).

643464351651 is a wasteful number, since it uses less digits than its factorization.

643464351651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8764.

The product of its digits is 3110400, while the sum is 48.

The spelling of 643464351651 in words is "six hundred forty-three billion, four hundred sixty-four million, three hundred fifty-one thousand, six hundred fifty-one".