643725 has 18 divisors (see below), whose sum is σ = 1153386. Its totient is φ = 343200.

The previous prime is 643723. The next prime is 643729. The reversal of 643725 is 527346.

It is a happy number.

643725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 49284 + 594441 = 222^2 + 771^2 .

It is not a de Polignac number, because 643725 - 2¹ = 643723 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643723) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1206 + ... + 1655.

It is an arithmetic number, because the mean of its divisors is an integer number (64077).

2⁶⁴³⁷²⁵ is an apocalyptic number.

It is an amenable number.

643725 is a deficient number, since it is larger than the sum of its proper divisors (509661).

643725 is a wasteful number, since it uses less digits than its factorization.

643725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2877 (or 2869 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 643725 is about 802.3247472190. The cubic root of 643725 is about 86.3442573828.

The spelling of 643725 in words is "six hundred forty-three thousand, seven hundred twenty-five".