842 has 4 divisors (see below), whose sum is σ = 1266. Its totient is φ = 420.

The previous prime is 839. The next prime is 853. The reversal of 842 is 248.

842 is nontrivially palindromic in base 11.

842 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 29²+1.

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

It can be written as a sum of positive squares in only one way, i.e., 841 + 1 = 29^2 + 1^2 .

842 is an undulating number in base 11.

It is a plaindrome in base 9 and base 16.

It is a nialpdrome in base 10 and base 14.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 209 + ... + 212.

2⁸⁴² is an apocalyptic number.

842 is a deficient number, since it is larger than the sum of its proper divisors (424).

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

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

The sum of its prime factors is 423.

The product of its digits is 64, while the sum is 14.

The square root of 842 is about 29.0172362571. The cubic root of 842 is about 9.4428704284.

Subtracting from 842 its sum of digits (14), we obtain a palindrome (828).

The spelling of 842 in words is "eight hundred forty-two", and thus it is an aban number.