211021221221100 has 216 divisors, whose sum is σ = 664368980424240. Its totient is φ = 56023133760000.

The previous prime is 211021221221081. The next prime is 211021221221101. The reversal of 211021221221100 is 1122122120112.

211021221221100 is a `hidden beast` number, since 2 + 110 + 212 + 21 + 221 + 100 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (211021221221101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 210711550 + ... + 211710650.

Almost surely, 2^{211021221221100} is an apocalyptic number.

211021221221100 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 211021221221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332184490212120).

211021221221100 is an abundant number, since it is smaller than the sum of its proper divisors (453347759203140).

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

211021221221100 is a wasteful number, since it uses less digits than its factorization.

211021221221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000161 (or 1000151 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 211021221221100 its reverse (1122122120112), we get a palindrome (212143343341212).

The spelling of 211021221221100 in words is "two hundred eleven trillion, twenty-one billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred".