21212031302100 has 432 divisors, whose sum is σ = 69976464313392. Its totient is φ = 5368529387520.

The previous prime is 21212031302093. The next prime is 21212031302101. The reversal of 21212031302100 is 120313021212.

21212031302100 is a `hidden beast` number, since 2 + 121 + 20 + 313 + 0 + 210 + 0 = 666.

It can be written as a sum of positive squares in 24 ways, for example, as 1963507167504 + 19248524134596 = 1401252^2 + 4387314^2 .

It is a super-2 number, since 2×21212031302100² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212031302101) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 305292964 + ... + 305362436.

It is an arithmetic number, because the mean of its divisors is an integer number (161982556281).

Almost surely, 2^{21212031302100} is an apocalyptic number.

21212031302100 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 21212031302100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34988232156696).

21212031302100 is an abundant number, since it is smaller than the sum of its proper divisors (48764433011292).

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

21212031302100 is a wasteful number, since it uses less digits than its factorization.

21212031302100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69756 (or 69746 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21212031302100 its reverse (120313021212), we get a palindrome (21332344323312).

The spelling of 21212031302100 in words is "twenty-one trillion, two hundred twelve billion, thirty-one million, three hundred two thousand, one hundred".