82171385 has 4 divisors (see below), whose sum is σ = 98605668. Its totient is φ = 65737104.

The previous prime is 82171373. The next prime is 82171391. The reversal of 82171385 is 58317128.

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

It can be written as a sum of positive squares in 2 ways, for example, as 51079609 + 31091776 = 7147^2 + 5576^2 .

It is a cyclic number.

It is not a de Polignac number, because 82171385 - 2¹² = 82167289 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 8217134 + ... + 8217143.

It is an arithmetic number, because the mean of its divisors is an integer number (24651417).

Almost surely, 2^82171385 is an apocalyptic number.

It is an amenable number.

82171385 is a deficient number, since it is larger than the sum of its proper divisors (16434283).

82171385 is a wasteful number, since it uses less digits than its factorization.

82171385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16434282.

The product of its digits is 13440, while the sum is 35.

The square root of 82171385 is about 9064.8433522042. The cubic root of 82171385 is about 434.7506123258.

The spelling of 82171385 in words is "eighty-two million, one hundred seventy-one thousand, three hundred eighty-five".