81137165 has 8 divisors (see below), whose sum is σ = 97417728. Its totient is φ = 64874320.

The previous prime is 81137159. The next prime is 81137179. The reversal of 81137165 is 56173118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81137165 - 2²² = 76942861 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9824 + ... + 16086.

It is an arithmetic number, because the mean of its divisors is an integer number (12177216).

Almost surely, 2^81137165 is an apocalyptic number.

It is an amenable number.

81137165 is a deficient number, since it is larger than the sum of its proper divisors (16280563).

81137165 is a wasteful number, since it uses less digits than its factorization.

81137165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8859.

The product of its digits is 5040, while the sum is 32.

The square root of 81137165 is about 9007.6170544712. The cubic root of 81137165 is about 432.9189631926.

The spelling of 81137165 in words is "eighty-one million, one hundred thirty-seven thousand, one hundred sixty-five".