643678763 has 16 divisors (see below), whose sum is σ = 793927680. Its totient is φ = 508186656.

The previous prime is 643678753. The next prime is 643678787. The reversal of 643678763 is 367876346.

643678763 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 643678763 - 2⁸ = 643678507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643678753) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36206 + ... + 50972.

It is an arithmetic number, because the mean of its divisors is an integer number (49620480).

Almost surely, 2^643678763 is an apocalyptic number.

643678763 is a deficient number, since it is larger than the sum of its proper divisors (150248917).

643678763 is a wasteful number, since it uses less digits than its factorization.

643678763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15266.

The product of its digits is 3048192, while the sum is 50.

The square root of 643678763 is about 25370.8250358557. The cubic root of 643678763 is about 863.4219004295.

The spelling of 643678763 in words is "six hundred forty-three million, six hundred seventy-eight thousand, seven hundred sixty-three".