643235424 has 96 divisors (see below), whose sum is σ = 1914151680. Its totient is φ = 187494912.

The previous prime is 643235393. The next prime is 643235431. The reversal of 643235424 is 424532346.

It is a tau number, because it is divible by the number of its divisors (96).

643235424 is a modest number, since divided by 35424 gives 6432 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10149 + ... + 37275.

It is an arithmetic number, because the mean of its divisors is an integer number (19939080).

Almost surely, 2^643235424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643235424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (957075840).

643235424 is an abundant number, since it is smaller than the sum of its proper divisors (1270916256).

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

643235424 is a wasteful number, since it uses less digits than its factorization.

643235424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27172 (or 27164 counting only the distinct ones).

The product of its digits is 69120, while the sum is 33.

The square root of 643235424 is about 25362.0863495100. The cubic root of 643235424 is about 863.2236252751.

The spelling of 643235424 in words is "six hundred forty-three million, two hundred thirty-five thousand, four hundred twenty-four".