643814 has 8 divisors (see below), whose sum is σ = 969168. Its totient is φ = 320760.

The previous prime is 643781. The next prime is 643847. The reversal of 643814 is 418346.

It is an interprime number because it is at equal distance from previous prime (643781) and next prime (643847).

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

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643814.

It is an unprimeable number.

643814 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 644 + ... + 1304.

It is an arithmetic number, because the mean of its divisors is an integer number (121146).

2⁶⁴³⁸¹⁴ is an apocalyptic number.

643814 is a deficient number, since it is larger than the sum of its proper divisors (325354).

643814 is a wasteful number, since it uses less digits than its factorization.

643814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150.

The product of its digits is 2304, while the sum is 26.

The square root of 643814 is about 802.3802091278. The cubic root of 643814 is about 86.3482364550.

The spelling of 643814 in words is "six hundred forty-three thousand, eight hundred fourteen".