21212112221200 has 30 divisors (see below), whose sum is σ = 50962099612394. Its totient is φ = 8484844888320.

The previous prime is 21212112221173. The next prime is 21212112221213. The reversal of 21212112221200 is 212221121212.

It can be written as a sum of positive squares in 3 ways, for example, as 452315431936 + 20759796789264 = 672544^2 + 4556292^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26515139877 + ... + 26515140676.

Almost surely, 2^{21212112221200} is an apocalyptic number.

21212112221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212112221200 is an abundant number, since it is smaller than the sum of its proper divisors (29749987391194).

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

21212112221200 is a wasteful number, since it uses less digits than its factorization.

21212112221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53030280571 (or 53030280560 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21212112221200 its reverse (212221121212), we get a palindrome (21424333342412).

The spelling of 21212112221200 in words is "twenty-one trillion, two hundred twelve billion, one hundred twelve million, two hundred twenty-one thousand, two hundred".