643726 has 8 divisors (see below), whose sum is σ = 991800. Its totient is φ = 313128.

The previous prime is 643723. The next prime is 643729. The reversal of 643726 is 627346.

643726 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (643723) and next prime (643729).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a d-powerful number, because it can be written as 6² + 4⁸ + 7² + 3¹² + 2³ + 6⁶ .

It is a junction number, because it is equal to n+sod(n) for n = 643694 and 643703.

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 3 ways as a sum of consecutive naturals, for example, 4276 + ... + 4423.

It is an arithmetic number, because the mean of its divisors is an integer number (123975).

2⁶⁴³⁷²⁶ is an apocalyptic number.

643726 is a deficient number, since it is larger than the sum of its proper divisors (348074).

643726 is a wasteful number, since it uses less digits than its factorization.

643726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8738.

The product of its digits is 6048, while the sum is 28.

The square root of 643726 is about 802.3253704078. The cubic root of 643726 is about 86.3443020935.

It can be divided in two parts, 643 and 726, that added together give a square (1369 = 37²).

The spelling of 643726 in words is "six hundred forty-three thousand, seven hundred twenty-six".