671684 has 12 divisors (see below), whose sum is σ = 1265964. Its totient is φ = 309984.

The previous prime is 671681. The next prime is 671701. The reversal of 671684 is 486176.

It can be written as a sum of positive squares in 2 ways, for example, as 222784 + 448900 = 472^2 + 670^2 .

It is an Ulam number.

It is a plaindrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 671684.

It is not an unprimeable number, because it can be changed into a prime (671681) by changing a digit.

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, 6407 + ... + 6510.

It is an arithmetic number, because the mean of its divisors is an integer number (105497).

2⁶⁷¹⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

671684 is a deficient number, since it is larger than the sum of its proper divisors (594280).

671684 is a wasteful number, since it uses less digits than its factorization.

671684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12934 (or 12932 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 671684 is about 819.5632983486. The cubic root of 671684 is about 87.5766512002.

The spelling of 671684 in words is "six hundred seventy-one thousand, six hundred eighty-four".