20817836585 has 48 divisors (see below), whose sum is σ = 30966551424. Its totient is φ = 13155158016.

The previous prime is 20817836581. The next prime is 20817836639. The reversal of 20817836585 is 58563871802.

It is not a de Polignac number, because 20817836585 - 2² = 20817836581 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20817836581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4037369 + ... + 4042521.

It is an arithmetic number, because the mean of its divisors is an integer number (645136488).

Almost surely, 2^20817836585 is an apocalyptic number.

It is an amenable number.

20817836585 is a deficient number, since it is larger than the sum of its proper divisors (10148714839).

20817836585 is a wasteful number, since it uses less digits than its factorization.

20817836585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5874 (or 5861 counting only the distinct ones).

The product of its (nonzero) digits is 3225600, while the sum is 53.

The spelling of 20817836585 in words is "twenty billion, eight hundred seventeen million, eight hundred thirty-six thousand, five hundred eighty-five".