81161175 has 12 divisors (see below), whose sum is σ = 134186600. Its totient is φ = 43285920.

The previous prime is 81161173. The next prime is 81161177. The reversal of 81161175 is 57116118.

It is an interprime number because it is at equal distance from previous prime (81161173) and next prime (81161177).

It is not a de Polignac number, because 81161175 - 2¹ = 81161173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81161173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 541000 + ... + 541149.

Almost surely, 2^81161175 is an apocalyptic number.

81161175 is a deficient number, since it is larger than the sum of its proper divisors (53025425).

81161175 is a wasteful number, since it uses less digits than its factorization.

81161175 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082162 (or 1082157 counting only the distinct ones).

The product of its digits is 1680, while the sum is 30.

The square root of 81161175 is about 9008.9497168094. The cubic root of 81161175 is about 432.9616619122.

The spelling of 81161175 in words is "eighty-one million, one hundred sixty-one thousand, one hundred seventy-five".