643934 has 8 divisors (see below), whose sum is σ = 969528. Its totient is φ = 320760.

The previous prime is 643927. The next prime is 643949. The reversal of 643934 is 439346.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 643897 and 643906.

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 643934.

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, 389 + ... + 1199.

It is an arithmetic number, because the mean of its divisors is an integer number (121191).

2⁶⁴³⁹³⁴ is an apocalyptic number.

643934 is a deficient number, since it is larger than the sum of its proper divisors (325594).

643934 is a wasteful number, since it uses less digits than its factorization.

643934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1210.

The product of its digits is 7776, while the sum is 29.

The square root of 643934 is about 802.4549831610. The cubic root of 643934 is about 86.3536009157.

The spelling of 643934 in words is "six hundred forty-three thousand, nine hundred thirty-four".