842621 has 4 divisors (see below), whose sum is σ = 907452. Its totient is φ = 777792.

The previous prime is 842617. The next prime is 842623. The reversal of 842621 is 126248.

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

It can be written as a sum of positive squares in 2 ways, for example, as 184900 + 657721 = 430^2 + 811^2 .

It is a cyclic number.

It is not a de Polignac number, because 842621 - 2² = 842617 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842623) 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, 32396 + ... + 32421.

It is an arithmetic number, because the mean of its divisors is an integer number (226863).

2⁸⁴²⁶²¹ is an apocalyptic number.

It is an amenable number.

842621 is a deficient number, since it is larger than the sum of its proper divisors (64831).

842621 is a wasteful number, since it uses less digits than its factorization.

842621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64830.

The product of its digits is 768, while the sum is 23.

The square root of 842621 is about 917.9438980679. The cubic root of 842621 is about 94.4519132374.

Adding to 842621 its reverse (126248), we get a palindrome (968869).

The spelling of 842621 in words is "eight hundred forty-two thousand, six hundred twenty-one".