800521 has 2 divisors, whose sum is σ = 800522. Its totient is φ = 800520.

The previous prime is 800519. The next prime is 800533. The reversal of 800521 is 125008.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 585225 + 215296 = 765^2 + 464^2 .

It is a cyclic number.

It is not a de Polignac number, because 800521 - 2¹ = 800519 is a prime.

Together with 800519, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 800495 and 800504.

It is not a weakly prime, because it can be changed into another prime (800221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400260 + 400261.

It is an arithmetic number, because the mean of its divisors is an integer number (400261).

2⁸⁰⁰⁵²¹ is an apocalyptic number.

It is an amenable number.

800521 is a deficient number, since it is larger than the sum of its proper divisors (1).

800521 is an equidigital number, since it uses as much as digits as its factorization.

800521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 800521 is about 894.7183914506. The cubic root of 800521 is about 92.8519245306.

Adding to 800521 its reverse (125008), we get a palindrome (925529).

The spelling of 800521 in words is "eight hundred thousand, five hundred twenty-one".