671605 has 8 divisors (see below), whose sum is σ = 879264. Its totient is φ = 488400.

The previous prime is 671603. The next prime is 671609. The reversal of 671605 is 506176.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 671605 - 2¹ = 671603 is a prime.

It is a Duffinian number.

671605 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 671605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6051 + ... + 6160.

It is an arithmetic number, because the mean of its divisors is an integer number (109908).

2⁶⁷¹⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

671605 is a deficient number, since it is larger than the sum of its proper divisors (207659).

671605 is a wasteful number, since it uses less digits than its factorization.

671605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12227.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 671605 is about 819.5151005320. The cubic root of 671605 is about 87.5732176279.

The spelling of 671605 in words is "six hundred seventy-one thousand, six hundred five".