643485736 has 16 divisors (see below), whose sum is σ = 1213763040. Its totient is φ = 319815600.

The previous prime is 643485719. The next prime is 643485737. The reversal of 643485736 is 637584346.

It is not an unprimeable number, because it can be changed into a prime (643485737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239490 + ... + 242161.

It is an arithmetic number, because the mean of its divisors is an integer number (75860190).

Almost surely, 2^643485736 is an apocalyptic number.

It is an amenable number.

643485736 is a deficient number, since it is larger than the sum of its proper divisors (570277304).

643485736 is a wasteful number, since it uses less digits than its factorization.

643485736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481824 (or 481820 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 46.

The square root of 643485736 is about 25367.0206370397. The cubic root of 643485736 is about 863.3355838737.

The spelling of 643485736 in words is "six hundred forty-three million, four hundred eighty-five thousand, seven hundred thirty-six".