20784885359281 has 12 divisors (see below), whose sum is σ = 21936586900932. Its totient is φ = 19690778548224.

The previous prime is 20784885359279. The next prime is 20784885359299. The reversal of 20784885359281 is 18295358848702.

It can be written as a sum of positive squares in 2 ways, for example, as 4995515554225 + 15789369805056 = 2235065^2 + 3973584^2 .

It is not a de Polignac number, because 20784885359281 - 2¹ = 20784885359279 is a prime.

It is a super-2 number, since 2×20784885359281² (a number of 27 digits) contains 22 as substring.

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 20784885359281.

It is not an unprimeable number, because it can be changed into a prime (20784882359281) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 76060965 + ... + 76333741.

It is an arithmetic number, because the mean of its divisors is an integer number (1828048908411).

Almost surely, 2^{20784885359281} is an apocalyptic number.

It is an amenable number.

20784885359281 is a deficient number, since it is larger than the sum of its proper divisors (1151701541651).

20784885359281 is a wasteful number, since it uses less digits than its factorization.

20784885359281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483888 (or 483869 counting only the distinct ones).

The product of its (nonzero) digits is 309657600, while the sum is 70.

The spelling of 20784885359281 in words is "twenty trillion, seven hundred eighty-four billion, eight hundred eighty-five million, three hundred fifty-nine thousand, two hundred eighty-one".