820580869 has 4 divisors (see below), whose sum is σ = 821826720. Its totient is φ = 819335020.

The previous prime is 820580833. The next prime is 820580921. The reversal of 820580869 is 968085028.

It is a happy number.

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 820580869 - 2⁷ = 820580741 is a prime.

It is a super-2 number, since 2×820580869² = 1346705925137590322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820580069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 621937 + ... + 623254.

It is an arithmetic number, because the mean of its divisors is an integer number (205456680).

Almost surely, 2^820580869 is an apocalyptic number.

It is an amenable number.

820580869 is a deficient number, since it is larger than the sum of its proper divisors (1245851).

820580869 is a wasteful number, since it uses less digits than its factorization.

820580869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1245850.

The product of its (nonzero) digits is 276480, while the sum is 46.

The square root of 820580869 is about 28645.7827437129. The cubic root of 820580869 is about 936.2111213960.

The spelling of 820580869 in words is "eight hundred twenty million, five hundred eighty thousand, eight hundred sixty-nine".