9920817971289 has 27 divisors (see below), whose sum is σ = 14372328386143. Its totient is φ = 6594432195984.

The previous prime is 9920817971261. The next prime is 9920817971297. The reversal of 9920817971289 is 9821797180299.

The square root of 9920817971289 is 3149733.

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

9920817971289 is a `hidden beast` number, since 9 + 9 + 208 + 1 + 79 + 71 + 289 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2341919090889 + 7578898880400 = 1530333^2 + 2752980^2 .

It is not a de Polignac number, because 9920817971289 - 2¹⁹ = 9920817447001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9920817971089) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3675737062 + ... + 3675739760.

Almost surely, 2^{9920817971289} is an apocalyptic number.

9920817971289 is the 3149733-rd square number.

9920817971289 is the 1574867-th centered octagonal number.

It is an amenable number.

9920817971289 is a deficient number, since it is larger than the sum of its proper divisors (4451510414854).

9920817971289 is an frugal number, since it uses more digits than its factorization.

9920817971289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6182 (or 3091 counting only the distinct ones).

The product of its (nonzero) digits is 82301184, while the sum is 72.

The spelling of 9920817971289 in words is "nine trillion, nine hundred twenty billion, eight hundred seventeen million, nine hundred seventy-one thousand, two hundred eighty-nine".