643233936 has 20 divisors (see below), whose sum is σ = 1661687792. Its totient is φ = 214411296.

The previous prime is 643233919. The next prime is 643233967. The reversal of 643233936 is 639332346.

It is a junction number, because it is equal to n+sod(n) for n = 643233894 and 643233903.

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, 6700306 + ... + 6700401.

Almost surely, 2^643233936 is an apocalyptic number.

It is an amenable number.

643233936 is an abundant number, since it is smaller than the sum of its proper divisors (1018453856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643233936 is a wasteful number, since it uses less digits than its factorization.

643233936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13400718 (or 13400712 counting only the distinct ones).

The product of its digits is 209952, while the sum is 39.

The square root of 643233936 is about 25362.0570143670. The cubic root of 643233936 is about 863.2229596412. Note that the first 3 decimals are identical.

The spelling of 643233936 in words is "six hundred forty-three million, two hundred thirty-three thousand, nine hundred thirty-six".