665331 has 8 divisors (see below), whose sum is σ = 890880. Its totient is φ = 441672.

The previous prime is 665311. The next prime is 665351. The reversal of 665331 is 133566.

It is an interprime number because it is at equal distance from previous prime (665311) and next prime (665351).

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

It is not a de Polignac number, because 665331 - 2⁵ = 665299 is a prime.

It is a super-2 number, since 2×665331² = 885330679122, which contains 22 as substring.

665331 is a lucky number.

It is a plaindrome in base 14.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (665311) 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 7 ways as a sum of consecutive naturals, for example, 1150 + ... + 1628.

It is an arithmetic number, because the mean of its divisors is an integer number (111360).

2⁶⁶⁵³³¹ is an apocalyptic number.

665331 is a deficient number, since it is larger than the sum of its proper divisors (225549).

665331 is a wasteful number, since it uses less digits than its factorization.

665331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 945.

The product of its digits is 1620, while the sum is 24.

The square root of 665331 is about 815.6782453885. The cubic root of 665331 is about 87.2996668530.

Adding to 665331 its reverse (133566), we get a palindrome (798897).

The spelling of 665331 in words is "six hundred sixty-five thousand, three hundred thirty-one".