643606 has 8 divisors (see below), whose sum is σ = 1016280. Its totient is φ = 304848.

The previous prime is 643589. The next prime is 643619. The reversal of 643606 is 606346.

It is a happy number.

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

It is a nialpdrome in base 15.

It is a congruent number.

It is an unprimeable number.

643606 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8431 + ... + 8506.

It is an arithmetic number, because the mean of its divisors is an integer number (127035).

2⁶⁴³⁶⁰⁶ is an apocalyptic number.

643606 is a deficient number, since it is larger than the sum of its proper divisors (372674).

643606 is a wasteful number, since it uses less digits than its factorization.

643606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16958.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 643606 is about 802.2505842940. The cubic root of 643606 is about 86.3389364772.

The spelling of 643606 in words is "six hundred forty-three thousand, six hundred six".