643078424 has 8 divisors (see below), whose sum is σ = 1205772060. Its totient is φ = 321539208.

The previous prime is 643078421. The next prime is 643078433. The reversal of 643078424 is 424870346.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643078421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40192394 + ... + 40192409.

Almost surely, 2^643078424 is an apocalyptic number.

It is an amenable number.

643078424 is a deficient number, since it is larger than the sum of its proper divisors (562693636).

643078424 is a wasteful number, since it uses less digits than its factorization.

643078424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80384809 (or 80384805 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 38.

The square root of 643078424 is about 25358.9909893907. The cubic root of 643078424 is about 863.1533880897.

The spelling of 643078424 in words is "six hundred forty-three million, seventy-eight thousand, four hundred twenty-four".