20545385305 has 4 divisors (see below), whose sum is σ = 24654462372. Its totient is φ = 16436308240.

The previous prime is 20545385303. The next prime is 20545385323. The reversal of 20545385305 is 50358354502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2284457616 + 18260927689 = 47796^2 + 135133^2 .

It is not a de Polignac number, because 20545385305 - 2¹ = 20545385303 is a prime.

It is a super-2 number, since 2×20545385305² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20545385303) 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 in 3 ways as a sum of consecutive naturals, for example, 2054538526 + ... + 2054538535.

It is an arithmetic number, because the mean of its divisors is an integer number (6163615593).

Almost surely, 2^20545385305 is an apocalyptic number.

It is an amenable number.

20545385305 is a deficient number, since it is larger than the sum of its proper divisors (4109077067).

20545385305 is an equidigital number, since it uses as much as digits as its factorization.

20545385305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4109077066.

The product of its (nonzero) digits is 360000, while the sum is 40.

The spelling of 20545385305 in words is "twenty billion, five hundred forty-five million, three hundred eighty-five thousand, three hundred five".