842531 has 2 divisors, whose sum is σ = 842532. Its totient is φ = 842530.

The previous prime is 842521. The next prime is 842551. The reversal of 842531 is 135248.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-842531 is a prime.

It is a super-3 number, since 3×842531³ = 1794233340105621873, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 842497 and 842506.

It is not a weakly prime, because it can be changed into another prime (842521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421265 + 421266.

It is an arithmetic number, because the mean of its divisors is an integer number (421266).

2⁸⁴²⁵³¹ is an apocalyptic number.

842531 is a deficient number, since it is larger than the sum of its proper divisors (1).

842531 is an equidigital number, since it uses as much as digits as its factorization.

842531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 23.

The square root of 842531 is about 917.8948741550. The cubic root of 842531 is about 94.4485503277.

Adding to 842531 its reverse (135248), we get a palindrome (977779).

The spelling of 842531 in words is "eight hundred forty-two thousand, five hundred thirty-one".