660609 has 16 divisors (see below), whose sum is σ = 1003200. Its totient is φ = 429408.

The previous prime is 660607. The next prime is 660617. The reversal of 660609 is 906066.

It is not a de Polignac number, because 660609 - 2¹ = 660607 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

660609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (660601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 877 + ... + 1445.

It is an arithmetic number, because the mean of its divisors is an integer number (62700).

2⁶⁶⁰⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

660609 is a deficient number, since it is larger than the sum of its proper divisors (342591).

660609 is a wasteful number, since it uses less digits than its factorization.

660609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621 (or 615 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 660609 is about 812.7785676308. The cubic root of 660609 is about 87.0926480323.

The spelling of 660609 in words is "six hundred sixty thousand, six hundred nine".