643854 has 8 divisors (see below), whose sum is σ = 1287720. Its totient is φ = 214616.

The previous prime is 643849. The next prime is 643859. The reversal of 643854 is 458346.

643854 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 (643849) and next prime (643859).

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

643854 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643859) 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, 53649 + ... + 53660.

It is an arithmetic number, because the mean of its divisors is an integer number (160965).

2⁶⁴³⁸⁵⁴ is an apocalyptic number.

643854 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

643854 is a wasteful number, since it uses less digits than its factorization.

643854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107314.

The product of its digits is 11520, while the sum is 30.

The square root of 643854 is about 802.4051345798. The cubic root of 643854 is about 86.3500246826.

The spelling of 643854 in words is "six hundred forty-three thousand, eight hundred fifty-four".