667609 has 4 divisors (see below), whose sum is σ = 690660. Its totient is φ = 644560.

The previous prime is 667577. The next prime is 667631. The reversal of 667609 is 906766.

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 205209 + 462400 = 453^2 + 680^2 .

It is a cyclic number.

It is not a de Polignac number, because 667609 - 2⁵ = 667577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667649) 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, 11482 + ... + 11539.

It is an arithmetic number, because the mean of its divisors is an integer number (172665).

2⁶⁶⁷⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

667609 is a deficient number, since it is larger than the sum of its proper divisors (23051).

667609 is a wasteful number, since it uses less digits than its factorization.

667609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23050.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 667609 is about 817.0734361121. The cubic root of 667609 is about 87.3991872951.

The spelling of 667609 in words is "six hundred sixty-seven thousand, six hundred nine".