665215212 has 12 divisors (see below), whose sum is σ = 1552168856. Its totient is φ = 221738400.

The previous prime is 665215207. The next prime is 665215237. The reversal of 665215212 is 212512566.

665215212 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×665215212² = 885022556552409888, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 665215212.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27717289 + ... + 27717312.

Almost surely, 2^665215212 is an apocalyptic number.

It is an amenable number.

665215212 is an abundant number, since it is smaller than the sum of its proper divisors (886953644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665215212 is a wasteful number, since it uses less digits than its factorization.

665215212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55434608 (or 55434606 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 665215212 is about 25791.7663606043. The cubic root of 665215212 is about 872.9460228604.

Adding to 665215212 its reverse (212512566), we get a palindrome (877727778).

The spelling of 665215212 in words is "six hundred sixty-five million, two hundred fifteen thousand, two hundred twelve".