121211200109 has 2 divisors, whose sum is σ = 121211200110. Its totient is φ = 121211200108.

The previous prime is 121211200091. The next prime is 121211200129. The reversal of 121211200109 is 901002112121.

Together with previous prime (121211200091) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (121211200129) can be obtained adding 121211200109 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97841963209 + 23369236900 = 312797^2 + 152870^2 .

It is a cyclic number.

It is not a de Polignac number, because 121211200109 - 2²⁰ = 121210151533 is a prime.

It is a super-2 number, since 2×121211200109² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121211200129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60605600054 + 60605600055.

It is an arithmetic number, because the mean of its divisors is an integer number (60605600055).

Almost surely, 2^121211200109 is an apocalyptic number.

It is an amenable number.

121211200109 is a deficient number, since it is larger than the sum of its proper divisors (1).

121211200109 is an equidigital number, since it uses as much as digits as its factorization.

121211200109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 121211200109 in words is "one hundred twenty-one billion, two hundred eleven million, two hundred thousand, one hundred nine".