212221666320 has 80 divisors (see below), whose sum is σ = 662909303232. Its totient is φ = 56160432640.

The previous prime is 212221666303. The next prime is 212221666367. The reversal of 212221666320 is 23666122212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3343587 + ... + 3406466.

Almost surely, 2^212221666320 is an apocalyptic number.

212221666320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212221666320 is an abundant number, since it is smaller than the sum of its proper divisors (450687636912).

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

212221666320 is a wasteful number, since it uses less digits than its factorization.

212221666320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6750200 (or 6750194 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

Adding to 212221666320 its reverse (23666122212), we get a palindrome (235887788532).

The spelling of 212221666320 in words is "two hundred twelve billion, two hundred twenty-one million, six hundred sixty-six thousand, three hundred twenty".