820517 has 4 divisors (see below), whose sum is σ = 826560. Its totient is φ = 814476.

The previous prime is 820489. The next prime is 820537. The reversal of 820517 is 715028.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 820517 - 2¹⁰ = 819493 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 820492 and 820501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2813 + ... + 3090.

It is an arithmetic number, because the mean of its divisors is an integer number (206640).

2⁸²⁰⁵¹⁷ is an apocalyptic number.

It is an amenable number.

820517 is a deficient number, since it is larger than the sum of its proper divisors (6043).

820517 is a wasteful number, since it uses less digits than its factorization.

820517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6042.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 820517 is about 905.8239343272. The cubic root of 820517 is about 93.6186831115.

The spelling of 820517 in words is "eight hundred twenty thousand, five hundred seventeen".