665544413 has 4 divisors (see below), whose sum is σ = 665880348. Its totient is φ = 665208480.

The previous prime is 665544391. The next prime is 665544437. The reversal of 665544413 is 314445566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 376476409 + 289068004 = 19403^2 + 17002^2 .

It is a cyclic number.

It is not a de Polignac number, because 665544413 - 2²⁰ = 664495837 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 (665514413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164978 + ... + 168963.

It is an arithmetic number, because the mean of its divisors is an integer number (166470087).

Almost surely, 2^665544413 is an apocalyptic number.

It is an amenable number.

665544413 is a deficient number, since it is larger than the sum of its proper divisors (335935).

665544413 is a wasteful number, since it uses less digits than its factorization.

665544413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335934.

The product of its digits is 172800, while the sum is 38.

The square root of 665544413 is about 25798.1474722508. The cubic root of 665544413 is about 873.0899999805.

Adding to 665544413 its reverse (314445566), we get a palindrome (979989979).

The spelling of 665544413 in words is "six hundred sixty-five million, five hundred forty-four thousand, four hundred thirteen".