643862 has 8 divisors (see below), whose sum is σ = 1007856. Its totient is φ = 307912.

The previous prime is 643859. The next prime is 643873. The reversal of 643862 is 268346.

643862 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6953 + ... + 7044.

It is an arithmetic number, because the mean of its divisors is an integer number (125982).

2⁶⁴³⁸⁶² is an apocalyptic number.

643862 is a deficient number, since it is larger than the sum of its proper divisors (363994).

643862 is a wasteful number, since it uses less digits than its factorization.

643862 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14022.

The product of its digits is 6912, while the sum is 29.

The square root of 643862 is about 802.4101195773. The cubic root of 643862 is about 86.3503823193.

The spelling of 643862 in words is "six hundred forty-three thousand, eight hundred sixty-two".