665411 has 4 divisors (see below), whose sum is σ = 673512. Its totient is φ = 657312.

The previous prime is 665387. The next prime is 665419. The reversal of 665411 is 114566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 114566 = 2 ⋅57283.

It is a cyclic number.

It is not a de Polignac number, because 665411 - 2¹⁸ = 403267 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (665419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3926 + ... + 4091.

It is an arithmetic number, because the mean of its divisors is an integer number (168378).

2⁶⁶⁵⁴¹¹ is an apocalyptic number.

665411 is a deficient number, since it is larger than the sum of its proper divisors (8101).

665411 is an equidigital number, since it uses as much as digits as its factorization.

665411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8100.

The product of its digits is 720, while the sum is 23.

The square root of 665411 is about 815.7272828587. The cubic root of 665411 is about 87.3031657097.

Adding to 665411 its reverse (114566), we get a palindrome (779977).

The spelling of 665411 in words is "six hundred sixty-five thousand, four hundred eleven".