820580864 has 20 divisors (see below), whose sum is σ = 1639560054. Its totient is φ = 410290176.

The previous prime is 820580833. The next prime is 820580921. The reversal of 820580864 is 468085028.

It can be written as a sum of positive squares in only one way, i.e., 686020864 + 134560000 = 26192^2 + 11600^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 800837 + ... + 801860.

Almost surely, 2^820580864 is an apocalyptic number.

It is an amenable number.

820580864 is a deficient number, since it is larger than the sum of its proper divisors (818979190).

820580864 is an equidigital number, since it uses as much as digits as its factorization.

820580864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1602715 (or 1602699 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 41.

The square root of 820580864 is about 28645.7826564400. The cubic root of 820580864 is about 936.2111194945.

The spelling of 820580864 in words is "eight hundred twenty million, five hundred eighty thousand, eight hundred sixty-four".