820646404 has 12 divisors (see below), whose sum is σ = 1511717200. Its totient is φ = 388727208.

The previous prime is 820646381. The next prime is 820646473. The reversal of 820646404 is 404646028.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 820646404.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5398914 + ... + 5399065.

Almost surely, 2^820646404 is an apocalyptic number.

It is an amenable number.

820646404 is a deficient number, since it is larger than the sum of its proper divisors (691070796).

820646404 is a wasteful number, since it uses less digits than its factorization.

820646404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10798002 (or 10798000 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 34.

The square root of 820646404 is about 28646.9266065315. The cubic root of 820646404 is about 936.2360439701.

The spelling of 820646404 in words is "eight hundred twenty million, six hundred forty-six thousand, four hundred four".