512821 has 2 divisors, whose sum is σ = 512822. Its totient is φ = 512820.

The previous prime is 512819. The next prime is 512843. The reversal of 512821 is 128215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 509796 + 3025 = 714^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 512821 - 2¹ = 512819 is a prime.

Together with 512819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (512891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256410 + 256411.

It is an arithmetic number, because the mean of its divisors is an integer number (256411).

2⁵¹²⁸²¹ is an apocalyptic number.

It is an amenable number.

512821 is a deficient number, since it is larger than the sum of its proper divisors (1).

512821 is an equidigital number, since it uses as much as digits as its factorization.

512821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 160, while the sum is 19.

The square root of 512821 is about 716.1152141939. The cubic root of 512821 is about 80.0427375813.

The spelling of 512821 in words is "five hundred twelve thousand, eight hundred twenty-one".