20816605129 has 2 divisors, whose sum is σ = 20816605130. Its totient is φ = 20816605128.

The previous prime is 20816605099. The next prime is 20816605141. The reversal of 20816605129 is 92150661802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19909210000 + 907395129 = 141100^2 + 30123^2 .

It is a cyclic number.

It is not a de Polignac number, because 20816605129 - 2²⁵ = 20783050697 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20816605091 and 20816605100.

It is not a weakly prime, because it can be changed into another prime (20816605529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10408302564 + 10408302565.

It is an arithmetic number, because the mean of its divisors is an integer number (10408302565).

Almost surely, 2^20816605129 is an apocalyptic number.

It is an amenable number.

20816605129 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816605129 is an equidigital number, since it uses as much as digits as its factorization.

20816605129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 20816605129 in words is "twenty billion, eight hundred sixteen million, six hundred five thousand, one hundred twenty-nine".