665015 has 12 divisors (see below), whose sum is σ = 865224. Its totient is φ = 490464.

The previous prime is 665011. The next prime is 665017. The reversal of 665015 is 510566.

It is not a de Polignac number, because 665015 - 2² = 665011 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665011) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 452 + ... + 1238.

It is an arithmetic number, because the mean of its divisors is an integer number (72102).

2⁶⁶⁵⁰¹⁵ is an apocalyptic number.

665015 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

665015 is a deficient number, since it is larger than the sum of its proper divisors (200209).

665015 is a wasteful number, since it uses less digits than its factorization.

665015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818 (or 805 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 665015 is about 815.4845185532. The cubic root of 665015 is about 87.2858436265.

Subtracting from 665015 its reverse (510566), we obtain a square (154449 = 393²).

The spelling of 665015 in words is "six hundred sixty-five thousand, fifteen".