20816329993 has 2 divisors, whose sum is σ = 20816329994. Its totient is φ = 20816329992.

The previous prime is 20816329991. The next prime is 20816330063. The reversal of 20816329993 is 39992361802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13305161104 + 7511168889 = 115348^2 + 86667^2 .

It is a cyclic number.

It is not a de Polignac number, because 20816329993 - 2¹ = 20816329991 is a prime.

Together with 20816329991, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20816329993.

It is not a weakly prime, because it can be changed into another prime (20816329991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10408164996 + 10408164997.

It is an arithmetic number, because the mean of its divisors is an integer number (10408164997).

Almost surely, 2^20816329993 is an apocalyptic number.

It is an amenable number.

20816329993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816329993 is an equidigital number, since it uses as much as digits as its factorization.

20816329993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1259712, while the sum is 52.

The spelling of 20816329993 in words is "twenty billion, eight hundred sixteen million, three hundred twenty-nine thousand, nine hundred ninety-three".