818139 has 8 divisors (see below), whose sum is σ = 1246720. Its totient is φ = 467496.

The previous prime is 818123. The next prime is 818143. The reversal of 818139 is 931818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 818139 - 2⁴ = 818123 is a prime.

It is an Ulam number.

It is a Duffinian number.

818139 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 818139.

It is not an unprimeable number, because it can be changed into a prime (818189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19459 + ... + 19500.

It is an arithmetic number, because the mean of its divisors is an integer number (155840).

2⁸¹⁸¹³⁹ is an apocalyptic number.

818139 is a deficient number, since it is larger than the sum of its proper divisors (428581).

818139 is a wasteful number, since it uses less digits than its factorization.

818139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38969.

The product of its digits is 1728, while the sum is 30.

The square root of 818139 is about 904.5103647831. The cubic root of 818139 is about 93.5281545609.

The spelling of 818139 in words is "eight hundred eighteen thousand, one hundred thirty-nine".