643163738 has 16 divisors (see below), whose sum is σ = 1113935424. Its totient is φ = 272799360.

The previous prime is 643163723. The next prime is 643163767. The reversal of 643163738 is 837361346.

It is a junction number, because it is equal to n+sod(n) for n = 643163695 and 643163704.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235448 + ... + 238163.

It is an arithmetic number, because the mean of its divisors is an integer number (69620964).

Almost surely, 2^643163738 is an apocalyptic number.

643163738 is a deficient number, since it is larger than the sum of its proper divisors (470771686).

643163738 is a wasteful number, since it uses less digits than its factorization.

643163738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473717.

The product of its digits is 217728, while the sum is 41.

The square root of 643163738 is about 25360.6730588918. The cubic root of 643163738 is about 863.1915564837.

The spelling of 643163738 in words is "six hundred forty-three million, one hundred sixty-three thousand, seven hundred thirty-eight".