643708 has 12 divisors (see below), whose sum is σ = 1213240. Its totient is φ = 297072.

The previous prime is 643703. The next prime is 643723. The reversal of 643708 is 807346.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643703) by changing a digit.

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, 6138 + ... + 6241.

2⁶⁴³⁷⁰⁸ is an apocalyptic number.

It is an amenable number.

643708 is a deficient number, since it is larger than the sum of its proper divisors (569532).

643708 is a wasteful number, since it uses less digits than its factorization.

643708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12396 (or 12394 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 643708 is about 802.3141529351. The cubic root of 643708 is about 86.3434972936.

The spelling of 643708 in words is "six hundred forty-three thousand, seven hundred eight".