81137167 has 4 divisors (see below), whose sum is σ = 82280016. Its totient is φ = 79994320.

The previous prime is 81137159. The next prime is 81137179. The reversal of 81137167 is 76173118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81137167 - 2³ = 81137159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81137197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 571318 + ... + 571459.

It is an arithmetic number, because the mean of its divisors is an integer number (20570004).

Almost surely, 2^81137167 is an apocalyptic number.

81137167 is a deficient number, since it is larger than the sum of its proper divisors (1142849).

81137167 is a wasteful number, since it uses less digits than its factorization.

81137167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1142848.

The product of its digits is 7056, while the sum is 34.

The square root of 81137167 is about 9007.6171654883. The cubic root of 81137167 is about 432.9189667497.

The spelling of 81137167 in words is "eighty-one million, one hundred thirty-seven thousand, one hundred sixty-seven".