665503312 has 40 divisors (see below), whose sum is σ = 1330315400. Its totient is φ = 322278912.

The previous prime is 665503309. The next prime is 665503331. The reversal of 665503312 is 213305566.

It can be written as a sum of positive squares in 4 ways, for example, as 591267856 + 74235456 = 24316^2 + 8616^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133114 + ... + 138022.

It is an arithmetic number, because the mean of its divisors is an integer number (33257885).

Almost surely, 2^665503312 is an apocalyptic number.

It is an amenable number.

665503312 is a deficient number, since it is larger than the sum of its proper divisors (664812088).

665503312 is a wasteful number, since it uses less digits than its factorization.

665503312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5183 (or 5177 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 31.

The square root of 665503312 is about 25797.3508717465. The cubic root of 665503312 is about 873.0720269196.

Adding to 665503312 its reverse (213305566), we get a palindrome (878808878).

The spelling of 665503312 in words is "six hundred sixty-five million, five hundred three thousand, three hundred twelve".