643208832 has 288 divisors, whose sum is σ = 2212086240. Its totient is φ = 175703040.

The previous prime is 643208773. The next prime is 643208833. The reversal of 643208832 is 238802346.

643208832 is a `hidden beast` number, since 643 + 2 + 0 + 8 + 8 + 3 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (643208833) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7749463 + ... + 7749545.

It is an arithmetic number, because the mean of its divisors is an integer number (7680855).

Almost surely, 2^643208832 is an apocalyptic number.

643208832 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643208832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1106043120).

643208832 is an abundant number, since it is smaller than the sum of its proper divisors (1568877408).

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

643208832 is a wasteful number, since it uses less digits than its factorization.

643208832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 643208832 is about 25361.5620970003. The cubic root of 643208832 is about 863.2117295999.

The spelling of 643208832 in words is "six hundred forty-three million, two hundred eight thousand, eight hundred thirty-two".