843725921 has 8 divisors (see below), whose sum is σ = 880614504. Its totient is φ = 807614080.

The previous prime is 843725893. The next prime is 843725947. The reversal of 843725921 is 129527348.

It can be written as a sum of positive squares in 4 ways, for example, as 32615521 + 811110400 = 5711^2 + 28480^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 843725921 - 2¹⁰ = 843724897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (843725321) 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 7 ways as a sum of consecutive naturals, for example, 191966 + ... + 196311.

It is an arithmetic number, because the mean of its divisors is an integer number (110076813).

Almost surely, 2^843725921 is an apocalyptic number.

It is an amenable number.

843725921 is a deficient number, since it is larger than the sum of its proper divisors (36888583).

843725921 is a wasteful number, since it uses less digits than its factorization.

843725921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388371.

The product of its digits is 120960, while the sum is 41.

The square root of 843725921 is about 29046.9606155274. The cubic root of 843725921 is about 944.9317984056.

The spelling of 843725921 in words is "eight hundred forty-three million, seven hundred twenty-five thousand, nine hundred twenty-one".