844621 has 2 divisors, whose sum is σ = 844622. Its totient is φ = 844620.

The previous prime is 844619. The next prime is 844631. The reversal of 844621 is 126448.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 837225 + 7396 = 915^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 844621 - 2¹ = 844619 is a prime.

Together with 844619, it forms a pair of twin primes.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (844601) 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, 422310 + 422311.

It is an arithmetic number, because the mean of its divisors is an integer number (422311).

2⁸⁴⁴⁶²¹ is an apocalyptic number.

It is an amenable number.

844621 is a deficient number, since it is larger than the sum of its proper divisors (1).

844621 is an equidigital number, since it uses as much as digits as its factorization.

844621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 25.

The square root of 844621 is about 919.0326435987. The cubic root of 844621 is about 94.5265828559.

The spelling of 844621 in words is "eight hundred forty-four thousand, six hundred twenty-one".