643763673 has 32 divisors (see below), whose sum is σ = 1116568320. Its totient is φ = 358888320.

The previous prime is 643763657. The next prime is 643763717. The reversal of 643763673 is 376367346.

643763673 is a `hidden beast` number, since 6 + 4 + 3 + 7 + 636 + 7 + 3 = 666.

It is not a de Polignac number, because 643763673 - 2⁴ = 643763657 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (643763173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33790 + ... + 49287.

It is an arithmetic number, because the mean of its divisors is an integer number (34892760).

Almost surely, 2^643763673 is an apocalyptic number.

643763673 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

643763673 is a deficient number, since it is larger than the sum of its proper divisors (472804647).

643763673 is a wasteful number, since it uses less digits than its factorization.

643763673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83134 (or 83128 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 45.

The square root of 643763673 is about 25372.4983594442. The cubic root of 643763673 is about 863.4598644650.

The spelling of 643763673 in words is "six hundred forty-three million, seven hundred sixty-three thousand, six hundred seventy-three".