81169 has 8 divisors (see below), whose sum is σ = 91008. Its totient is φ = 71760.

The previous prime is 81163. The next prime is 81173. The reversal of 81169 is 96118.

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

It is a cyclic number.

It is not a de Polignac number, because 81169 - 2⁷ = 81041 is a prime.

It is a super-2 number, since 2×81169² = 13176813122, which contains 22 as substring.

It is a Duffinian number.

81169 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 439 + ... + 595.

It is an arithmetic number, because the mean of its divisors is an integer number (11376).

2⁸¹¹⁶⁹ is an apocalyptic number.

It is an amenable number.

81169 is a deficient number, since it is larger than the sum of its proper divisors (9839).

81169 is a wasteful number, since it uses less digits than its factorization.

81169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215.

The product of its digits is 432, while the sum is 25.

The square root of 81169 is about 284.9017374464. The cubic root of 81169 is about 43.2975575856.

It can be divided in two parts, 81 and 169, that multiplied together give a square (13689 = 117²).

The spelling of 81169 in words is "eighty-one thousand, one hundred sixty-nine".