820769 has 4 divisors (see below), whose sum is σ = 823296. Its totient is φ = 818244.

The previous prime is 820763. The next prime is 820789. The reversal of 820769 is 967028.

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 820769 - 2⁴ = 820753 is a prime.

It is a super-2 number, since 2×820769² = 1347323502722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (820763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 689 + ... + 1454.

It is an arithmetic number, because the mean of its divisors is an integer number (205824).

2⁸²⁰⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

820769 is a deficient number, since it is larger than the sum of its proper divisors (2527).

820769 is a wasteful number, since it uses less digits than its factorization.

820769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2526.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 820769 is about 905.9630235280. The cubic root of 820769 is about 93.6282662944.

The spelling of 820769 in words is "eight hundred twenty thousand, seven hundred sixty-nine".