21121122222200 has 384 divisors, whose sum is σ = 66836592184320. Its totient is φ = 5993558323200.

The previous prime is 21121122222163. The next prime is 21121122222229. The reversal of 21121122222200 is 222222112112.

It is a super-2 number, since 2×21121122222200² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13891997 + ... + 15337203.

It is an arithmetic number, because the mean of its divisors is an integer number (174053625480).

Almost surely, 2^{21121122222200} is an apocalyptic number.

21121122222200 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 21121122222200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33418296092160).

21121122222200 is an abundant number, since it is smaller than the sum of its proper divisors (45715469962120).

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

21121122222200 is a wasteful number, since it uses less digits than its factorization.

21121122222200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1445327 (or 1445318 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21121122222200 its reverse (222222112112), we get a palindrome (21343344334312).

The spelling of 21121122222200 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twenty-two million, two hundred twenty-two thousand, two hundred".