845021 has 2 divisors, whose sum is σ = 845022. Its totient is φ = 845020.

The previous prime is 845017. The next prime is 845027. The reversal of 845021 is 120548.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 784996 + 60025 = 886^2 + 245^2 .

It is a cyclic number.

It is not a de Polignac number, because 845021 - 2² = 845017 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 844984 and 845002.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 845021.

It is not a weakly prime, because it can be changed into another prime (845027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422510 + 422511.

It is an arithmetic number, because the mean of its divisors is an integer number (422511).

2⁸⁴⁵⁰²¹ is an apocalyptic number.

It is an amenable number.

845021 is a deficient number, since it is larger than the sum of its proper divisors (1).

845021 is an equidigital number, since it uses as much as digits as its factorization.

845021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 845021 is about 919.2502379657. The cubic root of 845021 is about 94.5415026309.

Adding to 845021 its reverse (120548), we get a palindrome (965569).

The spelling of 845021 in words is "eight hundred forty-five thousand, twenty-one".