646808 has 16 divisors (see below), whose sum is σ = 1221480. Its totient is φ = 321088.

The previous prime is 646781. The next prime is 646823. The reversal of 646808 is 808646.

It is a congruent number.

It is an unprimeable 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, 1691 + ... + 2037.

2⁶⁴⁶⁸⁰⁸ is an apocalyptic number.

It is an amenable number.

646808 is a deficient number, since it is larger than the sum of its proper divisors (574672).

646808 is a wasteful number, since it uses less digits than its factorization.

646808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 586 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 646808 is about 804.2437441473. The cubic root of 646808 is about 86.4818811103.

The spelling of 646808 in words is "six hundred forty-six thousand, eight hundred eight".