842278639 has 4 divisors (see below), whose sum is σ = 871322760. Its totient is φ = 813234520.

The previous prime is 842278637. The next prime is 842278687. The reversal of 842278639 is 936872248.

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 842278639 - 2¹ = 842278637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 842278592 and 842278601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842278637) 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, 14522017 + ... + 14522074.

It is an arithmetic number, because the mean of its divisors is an integer number (217830690).

Almost surely, 2^842278639 is an apocalyptic number.

842278639 is a deficient number, since it is larger than the sum of its proper divisors (29044121).

842278639 is a wasteful number, since it uses less digits than its factorization.

842278639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29044120.

The product of its digits is 1161216, while the sum is 49.

The square root of 842278639 is about 29022.0371269834. The cubic root of 842278639 is about 944.3911941429.

The spelling of 842278639 in words is "eight hundred forty-two million, two hundred seventy-eight thousand, six hundred thirty-nine".