646908 has 48 divisors (see below), whose sum is σ = 1634304. Its totient is φ = 198720.

The previous prime is 646897. The next prime is 646909. The reversal of 646908 is 809646.

It is an Ulam number.

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 646908.

It is not an unprimeable number, because it can be changed into a prime (646909) by changing a digit.

646908 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 15 ways as a sum of consecutive naturals, for example, 13741 + ... + 13787.

It is an arithmetic number, because the mean of its divisors is an integer number (34048).

2⁶⁴⁶⁹⁰⁸ is an apocalyptic number.

It is an amenable number.

646908 is an abundant number, since it is smaller than the sum of its proper divisors (987396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646908 is a wasteful number, since it uses less digits than its factorization.

646908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 646908 is about 804.3059119514. The cubic root of 646908 is about 86.4863377355.

The spelling of 646908 in words is "six hundred forty-six thousand, nine hundred eight".