845921 has 2 divisors, whose sum is σ = 845922. Its totient is φ = 845920.

The previous prime is 845909. The next prime is 845927. The reversal of 845921 is 129548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 819025 + 26896 = 905^2 + 164^2 .

It is a cyclic number.

It is not a de Polignac number, because 845921 - 2¹⁰ = 844897 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 845921.

It is not a weakly prime, because it can be changed into another prime (845927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422960 + 422961.

It is an arithmetic number, because the mean of its divisors is an integer number (422961).

2⁸⁴⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

845921 is a deficient number, since it is larger than the sum of its proper divisors (1).

845921 is an equidigital number, since it uses as much as digits as its factorization.

845921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 29.

The square root of 845921 is about 919.7396370713. The cubic root of 845921 is about 94.5750549183.

The spelling of 845921 in words is "eight hundred forty-five thousand, nine hundred twenty-one".