667409 has 4 divisors (see below), whose sum is σ = 670320. Its totient is φ = 664500.

The previous prime is 667379. The next prime is 667417. The reversal of 667409 is 904766.

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 667409 - 2¹⁶ = 601873 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (667309) 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, 1079 + ... + 1580.

It is an arithmetic number, because the mean of its divisors is an integer number (167580).

2⁶⁶⁷⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

667409 is a deficient number, since it is larger than the sum of its proper divisors (2911).

667409 is a wasteful number, since it uses less digits than its factorization.

667409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2910.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 667409 is about 816.9510389246. The cubic root of 667409 is about 87.3904588411.

The spelling of 667409 in words is "six hundred sixty-seven thousand, four hundred nine".