844021321 has 36 divisors (see below), whose sum is σ = 1059798384. Its totient is φ = 666182400.

The previous prime is 844021303. The next prime is 844021349. The reversal of 844021321 is 123120448.

It is not a de Polignac number, because 844021321 - 2⁵ = 844021289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (844021351) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 536466 + ... + 538036.

It is an arithmetic number, because the mean of its divisors is an integer number (29438844).

Almost surely, 2^844021321 is an apocalyptic number.

It is an amenable number.

844021321 is a deficient number, since it is larger than the sum of its proper divisors (215777063).

844021321 is a wasteful number, since it uses less digits than its factorization.

844021321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1642 (or 1612 counting only the distinct ones).

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

The square root of 844021321 is about 29052.0450398935. The cubic root of 844021321 is about 945.0420633927.

Adding to 844021321 its reverse (123120448), we get a palindrome (967141769).

The spelling of 844021321 in words is "eight hundred forty-four million, twenty-one thousand, three hundred twenty-one".