20816551229 has 2 divisors, whose sum is σ = 20816551230. Its totient is φ = 20816551228.

The previous prime is 20816551213. The next prime is 20816551247. The reversal of 20816551229 is 92215561802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18714787204 + 2101764025 = 136802^2 + 45845^2 .

It is a cyclic number.

It is not a de Polignac number, because 20816551229 - 2⁴ = 20816551213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20816151229) 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, 10408275614 + 10408275615.

It is an arithmetic number, because the mean of its divisors is an integer number (10408275615).

Almost surely, 2^20816551229 is an apocalyptic number.

It is an amenable number.

20816551229 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816551229 is an equidigital number, since it uses as much as digits as its factorization.

20816551229 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 41.

The spelling of 20816551229 in words is "twenty billion, eight hundred sixteen million, five hundred fifty-one thousand, two hundred twenty-nine".