21222021100212 has 36 divisors (see below), whose sum is σ = 53843975492580. Its totient is φ = 7047709606272.

The previous prime is 21222021100193. The next prime is 21222021100237. The reversal of 21222021100212 is 21200112022212.

It is a happy number.

21222021100212 is a `hidden beast` number, since 21 + 2 + 220 + 211 + 0 + 0 + 212 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12318457374756 + 8903563725456 = 3509766^2 + 2983884^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1095716313 + ... + 1095735680.

It is an arithmetic number, because the mean of its divisors is an integer number (1495665985905).

Almost surely, 2^{21222021100212} is an apocalyptic number.

It is an amenable number.

21222021100212 is an abundant number, since it is smaller than the sum of its proper divisors (32621954392368).

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

21222021100212 is a wasteful number, since it uses less digits than its factorization.

21222021100212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2191452272 (or 2191452267 counting only the distinct ones).

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

Adding to 21222021100212 its reverse (21200112022212), we get a palindrome (42422133122424).

The spelling of 21222021100212 in words is "twenty-one trillion, two hundred twenty-two billion, twenty-one million, one hundred thousand, two hundred twelve".