663509 has 12 divisors (see below), whose sum is σ = 842688. Its totient is φ = 516600.

The previous prime is 663463. The next prime is 663517. The reversal of 663509 is 905366.

It is a de Polignac number, because none of the positive numbers 2^k-663509 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77 + ... + 1154.

It is an arithmetic number, because the mean of its divisors is an integer number (70224).

2⁶⁶³⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

663509 is a deficient number, since it is larger than the sum of its proper divisors (179179).

663509 is a wasteful number, since it uses less digits than its factorization.

663509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1256 (or 1249 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 663509 is about 814.5606177566. The cubic root of 663509 is about 87.2199043444.

The spelling of 663509 in words is "six hundred sixty-three thousand, five hundred nine".