21221121200 has 180 divisors, whose sum is σ = 53235171600. Its totient is φ = 8128834560.

The previous prime is 21221121167. The next prime is 21221121241. The reversal of 21221121200 is 212112212.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 66943442 + ... + 66943758.

Almost surely, 2^21221121200 is an apocalyptic number.

21221121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221121200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26617585800).

21221121200 is an abundant number, since it is smaller than the sum of its proper divisors (32014050400).

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

21221121200 is a wasteful number, since it uses less digits than its factorization.

21221121200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21221121200 its reverse (212112212), we get a palindrome (21433233412).

The spelling of 21221121200 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred".