9966181 has 4 divisors (see below), whose sum is σ = 10003500. Its totient is φ = 9928864.

The previous prime is 9966167. The next prime is 9966191. The reversal of 9966181 is 1816699.

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 1020100 + 8946081 = 1010^2 + 2991^2 .

It is a cyclic number.

It is not a de Polignac number, because 9966181 - 2¹¹ = 9964133 is a prime.

It is a super-2 number, since 2×9966181² = 198649527449522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9966191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18256 + ... + 18793.

It is an arithmetic number, because the mean of its divisors is an integer number (2500875).

Almost surely, 2^9966181 is an apocalyptic number.

It is an amenable number.

9966181 is a deficient number, since it is larger than the sum of its proper divisors (37319).

9966181 is a wasteful number, since it uses less digits than its factorization.

9966181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37318.

The product of its digits is 23328, while the sum is 40.

The square root of 9966181 is about 3156.9258781289. The cubic root of 9966181 is about 215.2003252783.

The spelling of 9966181 in words is "nine million, nine hundred sixty-six thousand, one hundred eighty-one".