20385538505 has 8 divisors (see below), whose sum is σ = 24482820552. Its totient is φ = 16294981248.

The previous prime is 20385538493. The next prime is 20385538517. The reversal of 20385538505 is 50583558302.

It is an interprime number because it is at equal distance from previous prime (20385538493) and next prime (20385538517).

It can be written as a sum of positive squares in 4 ways, for example, as 156450064 + 20229088441 = 12508^2 + 142229^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20385538505 - 2¹⁴ = 20385522121 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1674524 + ... + 1686653.

It is an arithmetic number, because the mean of its divisors is an integer number (3060352569).

Almost surely, 2^20385538505 is an apocalyptic number.

It is an amenable number.

20385538505 is a deficient number, since it is larger than the sum of its proper divisors (4097282047).

20385538505 is a wasteful number, since it uses less digits than its factorization.

20385538505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3362395.

The product of its (nonzero) digits is 720000, while the sum is 44.

The spelling of 20385538505 in words is "twenty billion, three hundred eighty-five million, five hundred thirty-eight thousand, five hundred five".