671816 has 16 divisors (see below), whose sum is σ = 1276800. Its totient is φ = 331344.

The previous prime is 671791. The next prime is 671831. The reversal of 671816 is 618176.

671816 is nontrivially palindromic in base 5.

It is a congruent number.

It is an unprimeable number.

671816 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101 + ... + 1163.

It is an arithmetic number, because the mean of its divisors is an integer number (79800).

2⁶⁷¹⁸¹⁶ is an apocalyptic number.

It is an amenable number.

671816 is a deficient number, since it is larger than the sum of its proper divisors (604984).

671816 is a wasteful number, since it uses less digits than its factorization.

671816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1148 (or 1144 counting only the distinct ones).

The product of its digits is 2016, while the sum is 29.

The square root of 671816 is about 819.6438250850. The cubic root of 671816 is about 87.5823877077.

The spelling of 671816 in words is "six hundred seventy-one thousand, eight hundred sixteen".