82138581 has 12 divisors (see below), whose sum is σ = 135593952. Its totient is φ = 46936296.

The previous prime is 82138549. The next prime is 82138597. The reversal of 82138581 is 18583128.

It is not a de Polignac number, because 82138581 - 2⁵ = 82138549 is a prime.

It is a super-2 number, since 2×82138581² = 13493492977387122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82138531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 651831 + ... + 651956.

It is an arithmetic number, because the mean of its divisors is an integer number (11299496).

Almost surely, 2^82138581 is an apocalyptic number.

It is an amenable number.

82138581 is a deficient number, since it is larger than the sum of its proper divisors (53455371).

82138581 is a wasteful number, since it uses less digits than its factorization.

82138581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303800 (or 1303797 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 82138581 is about 9063.0337635915. The cubic root of 82138581 is about 434.6927517242.

The spelling of 82138581 in words is "eighty-two million, one hundred thirty-eight thousand, five hundred eighty-one".