211220221212 has 960 divisors, whose sum is σ = 789025628160. Its totient is φ = 47449152000.

The previous prime is 211220221189. The next prime is 211220221259. The reversal of 211220221212 is 212122022112.

It is a happy number.

211220221212 is a `hidden beast` number, since 2 + 11 + 220 + 221 + 212 = 666.

211220221212 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×211220221212² (a number of 23 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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 930485443 + ... + 930485669.

It is an arithmetic number, because the mean of its divisors is an integer number (821901696).

Almost surely, 2^211220221212 is an apocalyptic number.

211220221212 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 211220221212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394512814080).

211220221212 is an abundant number, since it is smaller than the sum of its proper divisors (577805406948).

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

211220221212 is a wasteful number, since it uses less digits than its factorization.

211220221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444 (or 433 counting only the distinct ones).

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

Adding to 211220221212 its reverse (212122022112), we get a palindrome (423342243324).

Subtracting 211220221212 from its reverse (212122022112), we obtain a square (901800900 = 30030²).

The spelling of 211220221212 in words is "two hundred eleven billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twelve".