20698981085 has 4 divisors (see below), whose sum is σ = 24838777308. Its totient is φ = 16559184864.

The previous prime is 20698981067. The next prime is 20698981109. The reversal of 20698981085 is 58018989602.

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 9791894116 + 10907086969 = 98954^2 + 104437^2 .

It is a cyclic number.

It is not a de Polignac number, because 20698981085 - 2²² = 20694786781 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20698981085.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 2069898104 + ... + 2069898113.

It is an arithmetic number, because the mean of its divisors is an integer number (6209694327).

Almost surely, 2^20698981085 is an apocalyptic number.

It is an amenable number.

20698981085 is a deficient number, since it is larger than the sum of its proper divisors (4139796223).

20698981085 is an equidigital number, since it uses as much as digits as its factorization.

20698981085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4139796222.

The product of its (nonzero) digits is 2488320, while the sum is 56.

The spelling of 20698981085 in words is "twenty billion, six hundred ninety-eight million, nine hundred eighty-one thousand, eighty-five".