671391 has 12 divisors (see below), whose sum is σ = 1108432. Its totient is φ = 383616.

The previous prime is 671383. The next prime is 671401. The reversal of 671391 is 193176.

It is not a de Polignac number, because 671391 - 2³ = 671383 is a prime.

It is a Duffinian number.

671391 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 671391.

It is not an unprimeable number, because it can be changed into a prime (671591) 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 11 ways as a sum of consecutive naturals, for example, 5266 + ... + 5391.

2⁶⁷¹³⁹¹ is an apocalyptic number.

671391 is a deficient number, since it is larger than the sum of its proper divisors (437041).

671391 is a wasteful number, since it uses less digits than its factorization.

671391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10670 (or 10667 counting only the distinct ones).

The product of its digits is 1134, while the sum is 27.

The square root of 671391 is about 819.3845251163. The cubic root of 671391 is about 87.5639152059.

The spelling of 671391 in words is "six hundred seventy-one thousand, three hundred ninety-one".