671864 has 8 divisors (see below), whose sum is σ = 1259760. Its totient is φ = 335928.

The previous prime is 671851. The next prime is 671887. The reversal of 671864 is 468176.

It is a tau number, because it is divible by the number of its divisors (8).

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 671864.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41984 + ... + 41999.

It is an arithmetic number, because the mean of its divisors is an integer number (157470).

2⁶⁷¹⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

671864 is a deficient number, since it is larger than the sum of its proper divisors (587896).

671864 is a wasteful number, since it uses less digits than its factorization.

671864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83989 (or 83985 counting only the distinct ones).

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

The square root of 671864 is about 819.6731055732. The cubic root of 671864 is about 87.5844735241.

The spelling of 671864 in words is "six hundred seventy-one thousand, eight hundred sixty-four".