665575 has 12 divisors (see below), whose sum is σ = 838240. Its totient is φ = 524160.

The previous prime is 665573. The next prime is 665591. The reversal of 665575 is 575566.

It is not a de Polignac number, because 665575 - 2¹ = 665573 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

665575 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 665575.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665573) 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, 1807 + ... + 2143.

2⁶⁶⁵⁵⁷⁵ is an apocalyptic number.

665575 is a deficient number, since it is larger than the sum of its proper divisors (172665).

665575 is a wasteful number, since it uses less digits than its factorization.

665575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426 (or 421 counting only the distinct ones).

The product of its digits is 31500, while the sum is 34.

The square root of 665575 is about 815.8278004579. The cubic root of 665575 is about 87.3103374893.

Subtracting from 665575 its reverse (575566), we obtain a palindrome (90009).

It can be divided in two parts, 665 and 575, that multiplied together give a triangular number (382375 = T₈₇₄).

The spelling of 665575 in words is "six hundred sixty-five thousand, five hundred seventy-five".