221212400312 has 32 divisors (see below), whose sum is σ = 446371229520. Its totient is φ = 102393392640.

The previous prime is 221212400209. The next prime is 221212400323. The reversal of 221212400312 is 213004212122.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 13324178 + ... + 13340769.

Almost surely, 2^221212400312 is an apocalyptic number.

It is an amenable number.

221212400312 is an abundant number, since it is smaller than the sum of its proper divisors (225158829208).

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

221212400312 is a wasteful number, since it uses less digits than its factorization.

221212400312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26665031 (or 26665027 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 221212400312 its reverse (213004212122), we get a palindrome (434216612434).

The spelling of 221212400312 in words is "two hundred twenty-one billion, two hundred twelve million, four hundred thousand, three hundred twelve".