20385538506 has 24 divisors (see below), whose sum is σ = 45002039940. Its totient is φ = 6666968256.

The previous prime is 20385538493. The next prime is 20385538517. The reversal of 20385538506 is 60583558302.

It can be written as a sum of positive squares in 2 ways, for example, as 20378990025 + 6548481 = 142755^2 + 2559^2 .

It is a Curzon 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 11 ways as a sum of consecutive naturals, for example, 10683291 + ... + 10685198.

Almost surely, 2^20385538506 is an apocalyptic number.

20385538506 is an abundant number, since it is smaller than the sum of its proper divisors (24616501434).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20385538506 is a wasteful number, since it uses less digits than its factorization.

20385538506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21368550 (or 21368547 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 45.

The spelling of 20385538506 in words is "twenty billion, three hundred eighty-five million, five hundred thirty-eight thousand, five hundred six".