643655432 has 32 divisors (see below), whose sum is σ = 1380529920. Its totient is φ = 275598720.

The previous prime is 643655407. The next prime is 643655461. The reversal of 643655432 is 234556346.

It is a happy number.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

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, 64268 + ... + 73604.

It is an arithmetic number, because the mean of its divisors is an integer number (43141560).

Almost surely, 2^643655432 is an apocalyptic number.

It is an amenable number.

643655432 is an abundant number, since it is smaller than the sum of its proper divisors (736874488).

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

643655432 is a wasteful number, since it uses less digits than its factorization.

643655432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10581 (or 10577 counting only the distinct ones).

The product of its digits is 259200, while the sum is 38.

The square root of 643655432 is about 25370.3652319000. The cubic root of 643655432 is about 863.4114683419.

The spelling of 643655432 in words is "six hundred forty-three million, six hundred fifty-five thousand, four hundred thirty-two".