643735725 has 24 divisors (see below), whose sum is σ = 1082356320. Its totient is φ = 337504320.

The previous prime is 643735723. The next prime is 643735733. The reversal of 643735725 is 527537346.

643735725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643735725 - 2¹ = 643735723 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643735723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68314 + ... + 77163.

It is an arithmetic number, because the mean of its divisors is an integer number (45098180).

Almost surely, 2^643735725 is an apocalyptic number.

It is an amenable number.

643735725 is a deficient number, since it is larger than the sum of its proper divisors (438620595).

643735725 is a wasteful number, since it uses less digits than its factorization.

643735725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145549 (or 145544 counting only the distinct ones).

The product of its digits is 529200, while the sum is 42.

The square root of 643735725 is about 25371.9475996621. The cubic root of 643735725 is about 863.4473690278.

The spelling of 643735725 in words is "six hundred forty-three million, seven hundred thirty-five thousand, seven hundred twenty-five".