842221 has 4 divisors (see below), whose sum is σ = 847552. Its totient is φ = 836892.

The previous prime is 842209. The next prime is 842249. The reversal of 842221 is 122248.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 842221 - 2¹⁵ = 809453 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2421 + ... + 2746.

It is an arithmetic number, because the mean of its divisors is an integer number (211888).

2⁸⁴²²²¹ is an apocalyptic number.

It is an amenable number.

842221 is a deficient number, since it is larger than the sum of its proper divisors (5331).

842221 is a wasteful number, since it uses less digits than its factorization.

842221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5330.

The product of its digits is 256, while the sum is 19.

The square root of 842221 is about 917.7259939655. The cubic root of 842221 is about 94.4369651388.

Adding to 842221 its reverse (122248), we get a palindrome (964469).

The spelling of 842221 in words is "eight hundred forty-two thousand, two hundred twenty-one".