9937821181 has 4 divisors (see below), whose sum is σ = 10280504700. Its totient is φ = 9595137664.

The previous prime is 9937821167. The next prime is 9937821227. The reversal of 9937821181 is 1811287399.

9937821181 = 70490² + 70491².

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 4968981081 + 4968840100 = 70491^2 + 70490^2 .

It is not a de Polignac number, because 9937821181 - 2¹⁹ = 9937296893 is a prime.

It is a super-2 number, since 2×9937821181² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9937821281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171341716 + ... + 171341773.

It is an arithmetic number, because the mean of its divisors is an integer number (2570126175).

Almost surely, 2^9937821181 is an apocalyptic number.

9937821181 is the 70491-st centered square number.

It is an amenable number.

9937821181 is a deficient number, since it is larger than the sum of its proper divisors (342683519).

9937821181 is a wasteful number, since it uses less digits than its factorization.

9937821181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342683518.

The product of its digits is 217728, while the sum is 49.

The square root of 9937821181 is about 99688.6211209685. The cubic root of 9937821181 is about 2149.9600627880.

The spelling of 9937821181 in words is "nine billion, nine hundred thirty-seven million, eight hundred twenty-one thousand, one hundred eighty-one".