643886118 has 32 divisors (see below), whose sum is σ = 1515028320. Its totient is φ = 202003200.

The previous prime is 643886077. The next prime is 643886137. The reversal of 643886118 is 811688346.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349783 + ... + 351618.

It is an arithmetic number, because the mean of its divisors is an integer number (47344635).

Almost surely, 2^643886118 is an apocalyptic number.

643886118 is an abundant number, since it is smaller than the sum of its proper divisors (871142202).

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

643886118 is a wasteful number, since it uses less digits than its factorization.

643886118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701429 (or 701423 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 643886118 is about 25374.9111919628. The cubic root of 643886118 is about 863.5146048638.

The spelling of 643886118 in words is "six hundred forty-three million, eight hundred eighty-six thousand, one hundred eighteen".