8442139 has 4 divisors (see below), whose sum is σ = 8449056. Its totient is φ = 8435224.

The previous prime is 8442131. The next prime is 8442151. The reversal of 8442139 is 9312448.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 8442139 - 2³ = 8442131 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

8442139 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 8442139.

It is not an unprimeable number, because it can be changed into a prime (8442131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1084 + ... + 4249.

It is an arithmetic number, because the mean of its divisors is an integer number (2112264).

Almost surely, 2^8442139 is an apocalyptic number.

8442139 is a deficient number, since it is larger than the sum of its proper divisors (6917).

8442139 is a wasteful number, since it uses less digits than its factorization.

8442139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6916.

The product of its digits is 6912, while the sum is 31.

The square root of 8442139 is about 2905.5359230269. The cubic root of 8442139 is about 203.6186245817.

The spelling of 8442139 in words is "eight million, four hundred forty-two thousand, one hundred thirty-nine".