21212101122109 has 2 divisors, whose sum is σ = 21212101122110. Its totient is φ = 21212101122108.

The previous prime is 21212101121987. The next prime is 21212101122133. The reversal of 21212101122109 is 90122110121212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19145919116025 + 2066182006084 = 4375605^2 + 1437422^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212101122109 - 2³⁵ = 21177741383741 is a prime.

It is a super-3 number, since 3×21212101122109³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212101120109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606050561054 + 10606050561055.

It is an arithmetic number, because the mean of its divisors is an integer number (10606050561055).

Almost surely, 2^{21212101122109} is an apocalyptic number.

It is an amenable number.

21212101122109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212101122109 is an equidigital number, since it uses as much as digits as its factorization.

21212101122109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 25.

The spelling of 21212101122109 in words is "twenty-one trillion, two hundred twelve billion, one hundred one million, one hundred twenty-two thousand, one hundred nine".