821820304 has 40 divisors (see below), whose sum is σ = 1636736760. Its totient is φ = 399590400.

The previous prime is 821820301. The next prime is 821820347. The reversal of 821820304 is 403028128.

It can be written as a sum of positive squares in 4 ways, for example, as 2715904 + 819104400 = 1648^2 + 28620^2 .

It is a super-2 number, since 2×821820304² = 1350777224133304832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (821820301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82134 + ... + 91594.

It is an arithmetic number, because the mean of its divisors is an integer number (40918419).

Almost surely, 2^821820304 is an apocalyptic number.

It is an amenable number.

821820304 is a deficient number, since it is larger than the sum of its proper divisors (814916456).

821820304 is a wasteful number, since it uses less digits than its factorization.

821820304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9619 (or 9613 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 821820304 is about 28667.4083935050. The cubic root of 821820304 is about 936.6822466447.

The spelling of 821820304 in words is "eight hundred twenty-one million, eight hundred twenty thousand, three hundred four".