671808 has 28 divisors (see below), whose sum is σ = 1778000. Its totient is φ = 223872.

The previous prime is 671791. The next prime is 671831. The reversal of 671808 is 808176.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

671808 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, 1558 + ... + 1941.

It is an arithmetic number, because the mean of its divisors is an integer number (63500).

2⁶⁷¹⁸⁰⁸ is an apocalyptic number.

It is an amenable number.

671808 is an abundant number, since it is smaller than the sum of its proper divisors (1106192).

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

671808 is a wasteful number, since it uses less digits than its factorization.

671808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3514 (or 3504 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 671808 is about 819.6389449020. The cubic root of 671808 is about 87.5820400619.

The spelling of 671808 in words is "six hundred seventy-one thousand, eight hundred eight".