81382165 has 8 divisors (see below), whose sum is σ = 101904768. Its totient is φ = 62274960.

The previous prime is 81382163. The next prime is 81382177. The reversal of 81382165 is 56128318.

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

It is not a de Polignac number, because 81382165 - 2¹ = 81382163 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81382165.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81382163) 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, 353721 + ... + 353950.

It is an arithmetic number, because the mean of its divisors is an integer number (12738096).

Almost surely, 2^81382165 is an apocalyptic number.

It is an amenable number.

81382165 is a deficient number, since it is larger than the sum of its proper divisors (20522603).

81382165 is a wasteful number, since it uses less digits than its factorization.

81382165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707699.

The product of its digits is 11520, while the sum is 34.

The square root of 81382165 is about 9021.2064049106. The cubic root of 81382165 is about 433.3542695342.

The spelling of 81382165 in words is "eighty-one million, three hundred eighty-two thousand, one hundred sixty-five".