643887832 has 32 divisors (see below), whose sum is σ = 1407924000. Its totient is φ = 275950752.

The previous prime is 643887823. The next prime is 643887833. The reversal of 643887832 is 238788346.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643887833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114583 + ... + 120070.

It is an arithmetic number, because the mean of its divisors is an integer number (43997625).

Almost surely, 2^643887832 is an apocalyptic number.

It is an amenable number.

643887832 is an abundant number, since it is smaller than the sum of its proper divisors (764036168).

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

643887832 is a wasteful number, since it uses less digits than its factorization.

643887832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234680 (or 234662 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 49.

The square root of 643887832 is about 25374.9449654576. The cubic root of 643887832 is about 863.5153710773.

The spelling of 643887832 in words is "six hundred forty-three million, eight hundred eighty-seven thousand, eight hundred thirty-two".