643617630 has 64 divisors (see below), whose sum is σ = 1719532800. Its totient is φ = 171309600.

The previous prime is 643617617. The next prime is 643617673. The reversal of 643617630 is 36716346.

It is a happy number.

643617630 is a `hidden beast` number, since 6 + 4 + 3 + 6 + 17 + 630 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 165205 + ... + 169055.

It is an arithmetic number, because the mean of its divisors is an integer number (26867700).

Almost surely, 2^643617630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643617630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (859766400).

643617630 is an abundant number, since it is smaller than the sum of its proper divisors (1075915170).

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

643617630 is a wasteful number, since it uses less digits than its factorization.

643617630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4486 (or 4480 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 643617630 is about 25369.6202178905. The cubic root of 643617630 is about 863.3945652404.

The spelling of 643617630 in words is "six hundred forty-three million, six hundred seventeen thousand, six hundred thirty".