671709 has 4 divisors (see below), whose sum is σ = 895616. Its totient is φ = 447804.

The previous prime is 671701. The next prime is 671717. The reversal of 671709 is 907176.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (671701) and next prime (671717).

It is not a de Polignac number, because 671709 - 2³ = 671701 is a prime.

It is a D-number.

It is a Duffinian number.

671709 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671701) 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, 111949 + ... + 111954.

It is an arithmetic number, because the mean of its divisors is an integer number (223904).

2⁶⁷¹⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

671709 is a deficient number, since it is larger than the sum of its proper divisors (223907).

671709 is a wasteful number, since it uses less digits than its factorization.

671709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223906.

The product of its (nonzero) digits is 2646, while the sum is 30.

The square root of 671709 is about 819.5785502318. The cubic root of 671709 is about 87.5777377177.

The spelling of 671709 in words is "six hundred seventy-one thousand, seven hundred nine".