81167121 has 12 divisors (see below), whose sum is σ = 133990272. Its totient is φ = 46381176.

The previous prime is 81167089. The next prime is 81167137. The reversal of 81167121 is 12176118.

It is not a de Polignac number, because 81167121 - 2⁵ = 81167089 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81167171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 644121 + ... + 644246.

It is an arithmetic number, because the mean of its divisors is an integer number (11165856).

Almost surely, 2^81167121 is an apocalyptic number.

It is an amenable number.

81167121 is a deficient number, since it is larger than the sum of its proper divisors (52823151).

81167121 is a wasteful number, since it uses less digits than its factorization.

81167121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288380 (or 1288377 counting only the distinct ones).

The product of its digits is 672, while the sum is 27.

The square root of 81167121 is about 9009.2797159373. The cubic root of 81167121 is about 432.9722348131.

The spelling of 81167121 in words is "eighty-one million, one hundred sixty-seven thousand, one hundred twenty-one".