671309 has 4 divisors (see below), whose sum is σ = 673980. Its totient is φ = 668640.

The previous prime is 671303. The next prime is 671323. The reversal of 671309 is 903176.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 299209 + 372100 = 547^2 + 610^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671309 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 (671303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914 + ... + 1475.

It is an arithmetic number, because the mean of its divisors is an integer number (168495).

2⁶⁷¹³⁰⁹ is an apocalyptic number.

It is an amenable number.

671309 is a deficient number, since it is larger than the sum of its proper divisors (2671).

671309 is a wasteful number, since it uses less digits than its factorization.

671309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2670.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 671309 is about 819.3344860312. The cubic root of 671309 is about 87.5603502026.

The spelling of 671309 in words is "six hundred seventy-one thousand, three hundred nine".