20853243889 has 2 divisors, whose sum is σ = 20853243890. Its totient is φ = 20853243888.

The previous prime is 20853243881. The next prime is 20853243977. The reversal of 20853243889 is 98834235802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20186726400 + 666517489 = 142080^2 + 25817^2 .

It is a cyclic number.

It is not a de Polignac number, because 20853243889 - 2³ = 20853243881 is a prime.

It is not a weakly prime, because it can be changed into another prime (20853243881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10426621944 + 10426621945.

It is an arithmetic number, because the mean of its divisors is an integer number (10426621945).

Almost surely, 2^20853243889 is an apocalyptic number.

It is an amenable number.

20853243889 is a deficient number, since it is larger than the sum of its proper divisors (1).

20853243889 is an equidigital number, since it uses as much as digits as its factorization.

20853243889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3317760, while the sum is 52.

The spelling of 20853243889 in words is "twenty billion, eight hundred fifty-three million, two hundred forty-three thousand, eight hundred eighty-nine".