2121222221100 has 216 divisors, whose sum is σ = 6831361494048. Its totient is φ = 550144742400.

The previous prime is 2121222221057. The next prime is 2121222221123. The reversal of 2121222221100 is 11222221212.

It is a happy number.

2121222221100 is a `hidden beast` number, since 2 + 121 + 222 + 221 + 100 = 666.

It is a super-2 number, since 2×2121222221100² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 90264552 + ... + 90288048.

Almost surely, 2^{2121222221100} is an apocalyptic number.

2121222221100 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 2121222221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3415680747024).

2121222221100 is an abundant number, since it is smaller than the sum of its proper divisors (4710139272948).

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

2121222221100 is a wasteful number, since it uses less digits than its factorization.

2121222221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26265 (or 26255 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 2121222221100 its reverse (11222221212), we get a palindrome (2132444442312).

The spelling of 2121222221100 in words is "two trillion, one hundred twenty-one billion, two hundred twenty-two million, two hundred twenty-one thousand, one hundred".