21113126129 has 2 divisors, whose sum is σ = 21113126130. Its totient is φ = 21113126128.

The previous prime is 21113126107. The next prime is 21113126159. The reversal of 21113126129 is 92162131112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20924201104 + 188925025 = 144652^2 + 13745^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113126129 - 2¹² = 21113122033 is a prime.

It is not a weakly prime, because it can be changed into another prime (21113126159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556563064 + 10556563065.

It is an arithmetic number, because the mean of its divisors is an integer number (10556563065).

Almost surely, 2^21113126129 is an apocalyptic number.

It is an amenable number.

21113126129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113126129 is an equidigital number, since it uses as much as digits as its factorization.

21113126129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 29.

The spelling of 21113126129 in words is "twenty-one billion, one hundred thirteen million, one hundred twenty-six thousand, one hundred twenty-nine".