1211211212129 has 2 divisors, whose sum is σ = 1211211212130. Its totient is φ = 1211211212128.

The previous prime is 1211211212063. The next prime is 1211211212153. The reversal of 1211211212129 is 9212121121121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1060123522129 + 151087690000 = 1029623^2 + 388700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211211212129 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211211212098 and 1211211212107.

It is not a weakly prime, because it can be changed into another prime (1211211211129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605605606064 + 605605606065.

It is an arithmetic number, because the mean of its divisors is an integer number (605605606065).

Almost surely, 2^{1211211212129} is an apocalyptic number.

It is an amenable number.

1211211212129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211211212129 is an equidigital number, since it uses as much as digits as its factorization.

1211211212129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 26.

The spelling of 1211211212129 in words is "one trillion, two hundred eleven billion, two hundred eleven million, two hundred twelve thousand, one hundred twenty-nine".