643933345 has 16 divisors (see below), whose sum is σ = 853643520. Its totient is φ = 462384000.

The previous prime is 643933343. The next prime is 643933349. The reversal of 643933345 is 543339346.

It is not a de Polignac number, because 643933345 - 2¹ = 643933343 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643933298 and 643933307.

It is not an unprimeable number, because it can be changed into a prime (643933343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69756 + ... + 78445.

It is an arithmetic number, because the mean of its divisors is an integer number (53352720).

Almost surely, 2^643933345 is an apocalyptic number.

It is an amenable number.

643933345 is a deficient number, since it is larger than the sum of its proper divisors (209710175).

643933345 is a wasteful number, since it uses less digits than its factorization.

643933345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148296.

The product of its digits is 349920, while the sum is 40.

The square root of 643933345 is about 25375.8417594373. The cubic root of 643933345 is about 863.5357163648.

The spelling of 643933345 in words is "six hundred forty-three million, nine hundred thirty-three thousand, three hundred forty-five".