643943042 has 8 divisors (see below), whose sum is σ = 992020476. Its totient is φ = 313269552.

The previous prime is 643943039. The next prime is 643943059. The reversal of 643943042 is 240349346.

It can be written as a sum of positive squares in 2 ways, for example, as 642571801 + 1371241 = 25349^2 + 1171^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 643942993 and 643943011.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4350893 + ... + 4351040.

Almost surely, 2^643943042 is an apocalyptic number.

643943042 is a deficient number, since it is larger than the sum of its proper divisors (348077434).

643943042 is a wasteful number, since it uses less digits than its factorization.

643943042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8701972.

The product of its (nonzero) digits is 62208, while the sum is 35.

The square root of 643943042 is about 25376.0328262713. The cubic root of 643943042 is about 863.5400510080.

The spelling of 643943042 in words is "six hundred forty-three million, nine hundred forty-three thousand, forty-two".