671806 has 8 divisors (see below), whose sum is σ = 1067040. Its totient is φ = 316128.

The previous prime is 671791. The next prime is 671831. The reversal of 671806 is 608176.

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

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

671806 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, 9846 + ... + 9913.

It is an arithmetic number, because the mean of its divisors is an integer number (133380).

2⁶⁷¹⁸⁰⁶ is an apocalyptic number.

671806 is a deficient number, since it is larger than the sum of its proper divisors (395234).

671806 is a wasteful number, since it uses less digits than its factorization.

671806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19778.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 671806 is about 819.6377248517. The cubic root of 671806 is about 87.5819531501.

The spelling of 671806 in words is "six hundred seventy-one thousand, eight hundred six".