42839639 has 4 divisors (see below), whose sum is σ = 44702256. Its totient is φ = 40977024.

The previous prime is 42839611. The next prime is 42839647. The reversal of 42839639 is 93693824.

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 42839639 - 2¹² = 42835543 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42839639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42839659) 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, 931274 + ... + 931319.

It is an arithmetic number, because the mean of its divisors is an integer number (11175564).

Almost surely, 2^42839639 is an apocalyptic number.

42839639 is a deficient number, since it is larger than the sum of its proper divisors (1862617).

42839639 is a wasteful number, since it uses less digits than its factorization.

42839639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1862616.

The product of its digits is 279936, while the sum is 44.

The square root of 42839639 is about 6545.1996913769. The cubic root of 42839639 is about 349.9037531272.

The spelling of 42839639 in words is "forty-two million, eight hundred thirty-nine thousand, six hundred thirty-nine".