21212222120109 has 6 divisors (see below), whose sum is σ = 30639876395726. Its totient is φ = 14141481413400.

The previous prime is 21212222120081. The next prime is 21212222120129. The reversal of 21212222120109 is 90102122221212.

21212222120109 is a `hidden beast` number, since 2 + 1 + 212 + 222 + 120 + 109 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18757751564484 + 2454470555625 = 4331022^2 + 1566675^2 .

It is not a de Polignac number, because 21212222120109 - 2⁷ = 21212222119981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212222120129) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1178456784442 + ... + 1178456784459.

Almost surely, 2^{21212222120109} is an apocalyptic number.

It is an amenable number.

21212222120109 is a deficient number, since it is larger than the sum of its proper divisors (9427654275617).

21212222120109 is a wasteful number, since it uses less digits than its factorization.

21212222120109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2356913568907 (or 2356913568904 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The spelling of 21212222120109 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty-two million, one hundred twenty thousand, one hundred nine".