20704582138817 has 16 divisors (see below), whose sum is σ = 22140008273232. Its totient is φ = 19293690286080.

The previous prime is 20704582138787. The next prime is 20704582138831. The reversal of 20704582138817 is 71883128540702.

It can be written as a sum of positive squares in 8 ways, for example, as 79623294976 + 20624958843841 = 282176^2 + 4541471^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20704582138817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20704582138217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3919238 + ... + 7534559.

It is an arithmetic number, because the mean of its divisors is an integer number (1383750517077).

Almost surely, 2^{20704582138817} is an apocalyptic number.

It is an amenable number.

20704582138817 is a deficient number, since it is larger than the sum of its proper divisors (1435426134415).

20704582138817 is a wasteful number, since it uses less digits than its factorization.

20704582138817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11454868.

The product of its (nonzero) digits is 6021120, while the sum is 56.

The spelling of 20704582138817 in words is "twenty trillion, seven hundred four billion, five hundred eighty-two million, one hundred thirty-eight thousand, eight hundred seventeen".