805320820 has 12 divisors (see below), whose sum is σ = 1691173764. Its totient is φ = 322128320.

The previous prime is 805320809. The next prime is 805320823. The reversal of 805320820 is 28023508.

It can be written as a sum of positive squares in 2 ways, for example, as 564822756 + 240498064 = 23766^2 + 15508^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (805320823) 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, 20133001 + ... + 20133040.

It is an arithmetic number, because the mean of its divisors is an integer number (140931147).

Almost surely, 2^805320820 is an apocalyptic number.

It is an amenable number.

805320820 is an abundant number, since it is smaller than the sum of its proper divisors (885852944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

805320820 is a wasteful number, since it uses less digits than its factorization.

805320820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40266050 (or 40266048 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 805320820 is about 28378.1750646514. The cubic root of 805320820 is about 930.3713089338.

The spelling of 805320820 in words is "eight hundred five million, three hundred twenty thousand, eight hundred twenty".