819139 has 4 divisors (see below), whose sum is σ = 839160. Its totient is φ = 799120.

The previous prime is 819131. The next prime is 819149. The reversal of 819139 is 931918.

819139 is nontrivially palindromic in base 8.

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

It is a cyclic number.

It is not a de Polignac number, because 819139 - 2³ = 819131 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 819139.

It is not an unprimeable number, because it can be changed into a prime (819131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9949 + ... + 10030.

It is an arithmetic number, because the mean of its divisors is an integer number (209790).

2⁸¹⁹¹³⁹ is an apocalyptic number.

819139 is a deficient number, since it is larger than the sum of its proper divisors (20021).

819139 is a wasteful number, since it uses less digits than its factorization.

819139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20020.

The product of its digits is 1944, while the sum is 31.

The square root of 819139 is about 905.0629812339. The cubic root of 819139 is about 93.5662451032.

The spelling of 819139 in words is "eight hundred nineteen thousand, one hundred thirty-nine".