665501212 has 12 divisors (see below), whose sum is σ = 1166918760. Its totient is φ = 332095856.

The previous prime is 665501171. The next prime is 665501219. The reversal of 665501212 is 212105566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665501219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161398 + ... + 165469.

It is an arithmetic number, because the mean of its divisors is an integer number (97243230).

Almost surely, 2^665501212 is an apocalyptic number.

It is an amenable number.

665501212 is a deficient number, since it is larger than the sum of its proper divisors (501417548).

665501212 is a wasteful number, since it uses less digits than its factorization.

665501212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327380 (or 327378 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 665501212 is about 25797.3101698607. The cubic root of 665501212 is about 873.0711085905.

Adding to 665501212 its reverse (212105566), we get a palindrome (877606778).

The spelling of 665501212 in words is "six hundred sixty-five million, five hundred one thousand, two hundred twelve".