21212011110100 has 72 divisors (see below), whose sum is σ = 46266544486008. Its totient is φ = 8441218867200.

The previous prime is 21212011110097. The next prime is 21212011110133. The reversal of 21212011110100 is 101111021212.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 73680759364 + 21138330350736 = 271442^2 + 4597644^2 .

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 607550244 + ... + 607585156.

It is an arithmetic number, because the mean of its divisors is an integer number (642590895639).

Almost surely, 2^{21212011110100} is an apocalyptic number.

21212011110100 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 21212011110100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23133272243004).

21212011110100 is an abundant number, since it is smaller than the sum of its proper divisors (25054533375908).

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

21212011110100 is a wasteful number, since it uses less digits than its factorization.

21212011110100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65965 (or 65958 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21212011110100 its reverse (101111021212), we get a palindrome (21313122131312).

The spelling of 21212011110100 in words is "twenty-one trillion, two hundred twelve billion, eleven million, one hundred ten thousand, one hundred".