665530 has 8 divisors (see below), whose sum is σ = 1197972. Its totient is φ = 266208.

The previous prime is 665527. The next prime is 665549. The reversal of 665530 is 35566.

It can be written as a sum of positive squares in 2 ways, for example, as 613089 + 52441 = 783^2 + 229^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 14.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 665495 and 665504.

It is an unprimeable number.

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, 33267 + ... + 33286.

2⁶⁶⁵⁵³⁰ is an apocalyptic number.

665530 is a deficient number, since it is larger than the sum of its proper divisors (532442).

665530 is a wasteful number, since it uses less digits than its factorization.

665530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66560.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 665530 is about 815.8002206423. The cubic root of 665530 is about 87.3083697402.

It can be divided in two parts, 6 and 65530, that added together give a 16-th power (65536 = 2¹⁶).

The spelling of 665530 in words is "six hundred sixty-five thousand, five hundred thirty".