21212100121212 has 432 divisors, whose sum is σ = 74498518051776. Its totient is φ = 4948360243200.

The previous prime is 21212100121139. The next prime is 21212100121243.

21212100121212 is a `hidden beast` number, since 2 + 121 + 210 + 0 + 121 + 212 = 666.

21212100121212 is nontrivially palindromic in base 10.

21212100121212 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×21212100121212³ (a number of 41 digits) contains 333 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 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 143 ways as a sum of consecutive naturals, for example, 13943512 + ... + 15389792.

It is an arithmetic number, because the mean of its divisors is an integer number (172450273268).

Almost surely, 2^{21212100121212} is an apocalyptic number.

21212100121212 is a gapful number since it is divisible by the number (22) 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 21212100121212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37249259025888).

21212100121212 is an abundant number, since it is smaller than the sum of its proper divisors (53286417930564).

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

21212100121212 is a wasteful number, since it uses less digits than its factorization.

21212100121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1446370 (or 1446354 counting only the distinct ones).

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

It can be divided in two parts, 21212100 and 121212, that added together give a palindrome (21333312).

The spelling of 21212100121212 in words is "twenty-one trillion, two hundred twelve billion, one hundred million, one hundred twenty-one thousand, two hundred twelve".