831686139 has 12 divisors (see below), whose sum is σ = 1221019072. Its totient is φ = 545367600.

The previous prime is 831686117. The next prime is 831686159. The reversal of 831686139 is 931686138.

It is a happy number.

It is not a de Polignac number, because 831686139 - 2⁹ = 831685627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 831686094 and 831686103.

It is not an unprimeable number, because it can be changed into a prime (831686159) 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, 756907 + ... + 758004.

Almost surely, 2^831686139 is an apocalyptic number.

831686139 is a deficient number, since it is larger than the sum of its proper divisors (389332933).

831686139 is a wasteful number, since it uses less digits than its factorization.

831686139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1514978 (or 1514975 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 831686139 is about 28838.9691043213. The cubic root of 831686139 is about 940.4155922237.

Subtracting 831686139 from its reverse (931686138), we obtain a palindrome (99999999).

The spelling of 831686139 in words is "eight hundred thirty-one million, six hundred eighty-six thousand, one hundred thirty-nine".