21113120129 has 2 divisors, whose sum is σ = 21113120130. Its totient is φ = 21113120128.

The previous prime is 21113120117. The next prime is 21113120137. The reversal of 21113120129 is 92102131112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18434850625 + 2678269504 = 135775^2 + 51752^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113120129 - 2¹² = 21113116033 is a prime.

It is not a weakly prime, because it can be changed into another prime (21113126129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556560064 + 10556560065.

It is an arithmetic number, because the mean of its divisors is an integer number (10556560065).

Almost surely, 2^21113120129 is an apocalyptic number.

It is an amenable number.

21113120129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113120129 is an equidigital number, since it uses as much as digits as its factorization.

21113120129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 23.

The spelling of 21113120129 in words is "twenty-one billion, one hundred thirteen million, one hundred twenty thousand, one hundred twenty-nine".