20845873161 has 81 divisors (see below), whose sum is σ = 33986282421. Its totient is φ = 12308191488.

The previous prime is 20845873109. The next prime is 20845873201. The reversal of 20845873161 is 16137854802.

The square root of 20845873161 is 144381.

It is a perfect power (a square), and thus also a powerful number.

20845873161 is a `hidden beast` number, since 2 + 0 + 8 + 4 + 587 + 3 + 1 + 61 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 409455225 + 20436417936 = 20235^2 + 142956^2 .

It is not a de Polignac number, because 20845873161 - 2⁷ = 20845873033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20845873661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 139905115 + ... + 139905263.

Almost surely, 2^20845873161 is an apocalyptic number.

20845873161 is the 144381-st square number.

20845873161 is the 72191-st centered octagonal number.

It is an amenable number.

20845873161 is a deficient number, since it is larger than the sum of its proper divisors (13140409260).

20845873161 is a wasteful number, since it uses less digits than its factorization.

20845873161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 20845873161 in words is "twenty billion, eight hundred forty-five million, eight hundred seventy-three thousand, one hundred sixty-one".