643630776715 has 16 divisors (see below), whose sum is σ = 799595422848. Its totient is φ = 497045776896.

The previous prime is 643630776709. The next prime is 643630776721. The reversal of 643630776715 is 517677036346.

It is an interprime number because it is at equal distance from previous prime (643630776709) and next prime (643630776721).

It is a cyclic number.

It is not a de Polignac number, because 643630776715 - 2³¹ = 641483293067 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18742122 + ... + 18776431.

It is an arithmetic number, because the mean of its divisors is an integer number (49974713928).

Almost surely, 2^643630776715 is an apocalyptic number.

643630776715 is a deficient number, since it is larger than the sum of its proper divisors (155964646133).

643630776715 is a wasteful number, since it uses less digits than its factorization.

643630776715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37518678.

The product of its (nonzero) digits is 13335840, while the sum is 55.

The spelling of 643630776715 in words is "six hundred forty-three billion, six hundred thirty million, seven hundred seventy-six thousand, seven hundred fifteen".