643436044 has 6 divisors (see below), whose sum is σ = 1126013084. Its totient is φ = 321718020.

The previous prime is 643436033. The next prime is 643436069. The reversal of 643436044 is 440634346.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80429502 + ... + 80429509.

Almost surely, 2^643436044 is an apocalyptic number.

It is an amenable number.

643436044 is a deficient number, since it is larger than the sum of its proper divisors (482577040).

643436044 is a wasteful number, since it uses less digits than its factorization.

643436044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160859015 (or 160859013 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 34.

The square root of 643436044 is about 25366.0411574215. The cubic root of 643436044 is about 863.3133601351.

The spelling of 643436044 in words is "six hundred forty-three million, four hundred thirty-six thousand, forty-four".