671909 has 4 divisors (see below), whose sum is σ = 767904. Its totient is φ = 575916.

The previous prime is 671903. The next prime is 671911. The reversal of 671909 is 909176.

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 a cyclic number.

It is not a de Polignac number, because 671909 - 2⁴ = 671893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671903) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 47987 + ... + 48000.

It is an arithmetic number, because the mean of its divisors is an integer number (191976).

2⁶⁷¹⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

671909 is a deficient number, since it is larger than the sum of its proper divisors (95995).

671909 is an equidigital number, since it uses as much as digits as its factorization.

671909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95994.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 671909 is about 819.7005550809. The cubic root of 671909 is about 87.5864288867.

The spelling of 671909 in words is "six hundred seventy-one thousand, nine hundred nine".