643782 has 16 divisors (see below), whose sum is σ = 1319472. Its totient is φ = 209280.

The previous prime is 643781. The next prime is 643847. The reversal of 643782 is 287346.

643782 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1063 + ... + 1554.

It is an arithmetic number, because the mean of its divisors is an integer number (82467).

2⁶⁴³⁷⁸² is an apocalyptic number.

643782 is an abundant number, since it is smaller than the sum of its proper divisors (675690).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643782 is a wasteful number, since it uses less digits than its factorization.

643782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2663.

The product of its digits is 8064, while the sum is 30.

The square root of 643782 is about 802.3602682087. The cubic root of 643782 is about 86.3468058196.

The spelling of 643782 in words is "six hundred forty-three thousand, seven hundred eighty-two".