82139391 has 12 divisors (see below), whose sum is σ = 119071680. Its totient is φ = 54563040.

The previous prime is 82139377. The next prime is 82139423. The reversal of 82139391 is 19393128.

It is not a de Polignac number, because 82139391 - 2⁷ = 82139263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82139311) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 13711 + ... + 18768.

It is an arithmetic number, because the mean of its divisors is an integer number (9922640).

Almost surely, 2^82139391 is an apocalyptic number.

82139391 is a deficient number, since it is larger than the sum of its proper divisors (36932289).

82139391 is a wasteful number, since it uses less digits than its factorization.

82139391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32766 (or 32763 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 82139391 is about 9063.0784505046. The cubic root of 82139391 is about 434.6941806101.

The spelling of 82139391 in words is "eighty-two million, one hundred thirty-nine thousand, three hundred ninety-one".