643998116 has 24 divisors (see below), whose sum is σ = 1158562944. Its totient is φ = 313104960.

The previous prime is 643998107. The next prime is 643998133. The reversal of 643998116 is 611899346.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5201 + ... + 36263.

It is an arithmetic number, because the mean of its divisors is an integer number (48273456).

Almost surely, 2^643998116 is an apocalyptic number.

It is an amenable number.

643998116 is a deficient number, since it is larger than the sum of its proper divisors (514564828).

643998116 is a wasteful number, since it uses less digits than its factorization.

643998116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31211 (or 31209 counting only the distinct ones).

The product of its digits is 279936, while the sum is 47.

The square root of 643998116 is about 25377.1179608718. The cubic root of 643998116 is about 863.5646687386.

The spelling of 643998116 in words is "six hundred forty-three million, nine hundred ninety-eight thousand, one hundred sixteen".