1221012112129 has 2 divisors, whose sum is σ = 1221012112130. Its totient is φ = 1221012112128.

The previous prime is 1221012112081. The next prime is 1221012112237. The reversal of 1221012112129 is 9212112101221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 832911769600 + 388100342529 = 912640^2 + 622977^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221012112129 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221012112729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610506056064 + 610506056065.

It is an arithmetic number, because the mean of its divisors is an integer number (610506056065).

Almost surely, 2^{1221012112129} is an apocalyptic number.

It is an amenable number.

1221012112129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221012112129 is an equidigital number, since it uses as much as digits as its factorization.

1221012112129 is an evil number, because the sum of its binary digits is even.

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

The spelling of 1221012112129 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred twelve thousand, one hundred twenty-nine".