671863 has 4 divisors (see below), whose sum is σ = 693568. Its totient is φ = 650160.

The previous prime is 671851. The next prime is 671887. The reversal of 671863 is 368176.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 671863 - 2⁵ = 671831 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 21673 = 671863 / (6 + 7 + 1 + 8 + 6 + 3).

It is a Duffinian number.

671863 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10806 + ... + 10867.

It is an arithmetic number, because the mean of its divisors is an integer number (173392).

2⁶⁷¹⁸⁶³ is an apocalyptic number.

671863 is a deficient number, since it is larger than the sum of its proper divisors (21705).

671863 is a wasteful number, since it uses less digits than its factorization.

671863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21704.

The product of its digits is 6048, while the sum is 31.

The square root of 671863 is about 819.6724955737. The cubic root of 671863 is about 87.5844300706.

The spelling of 671863 in words is "six hundred seventy-one thousand, eight hundred sixty-three".