20512512505 has 16 divisors (see below), whose sum is σ = 24783905664. Its totient is φ = 16297562880.

The previous prime is 20512512469. The next prime is 20512512509. The reversal of 20512512505 is 50521521502.

It is not a de Polignac number, because 20512512505 - 2⁹ = 20512511993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20512512509) 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 15 ways as a sum of consecutive naturals, for example, 1223137 + ... + 1239793.

It is an arithmetic number, because the mean of its divisors is an integer number (1548994104).

Almost surely, 2^20512512505 is an apocalyptic number.

It is an amenable number.

20512512505 is a deficient number, since it is larger than the sum of its proper divisors (4271393159).

20512512505 is a wasteful number, since it uses less digits than its factorization.

20512512505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18336.

The product of its (nonzero) digits is 5000, while the sum is 28.

The spelling of 20512512505 in words is "twenty billion, five hundred twelve million, five hundred twelve thousand, five hundred five".