671886 has 24 divisors (see below), whose sum is σ = 1471080. Its totient is φ = 221616.

The previous prime is 671851. The next prime is 671887. The reversal of 671886 is 688176.

It is a self number, because there is not a number n which added to its sum of digits gives 671886.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671887) by changing a digit.

671886 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 (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2820 + ... + 3048.

It is an arithmetic number, because the mean of its divisors is an integer number (61295).

2⁶⁷¹⁸⁸⁶ is an apocalyptic number.

671886 is an abundant number, since it is smaller than the sum of its proper divisors (799194).

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

671886 is a wasteful number, since it uses less digits than its factorization.

671886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 397 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 671886 is about 819.6865254474. The cubic root of 671886 is about 87.5854294901.

Subtracting 671886 from its reverse (688176), we obtain a triangular number (16290 = T₁₈₀).

It can be divided in two parts, 67 and 1886, that added together give a triangular number (1953 = T₆₂).

The spelling of 671886 in words is "six hundred seventy-one thousand, eight hundred eighty-six".