820028100 has 36 divisors (see below), whose sum is σ = 2372615504. Its totient is φ = 218674080.

The previous prime is 820028093. The next prime is 820028117. The reversal of 820028100 is 1820028.

It is a super-2 number, since 2×820028100² = 1344892169579220000, which contains 22 as substring.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1366414 + ... + 1367013.

Almost surely, 2^820028100 is an apocalyptic number.

It is an amenable number.

820028100 is an abundant number, since it is smaller than the sum of its proper divisors (1552587404).

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

820028100 is a wasteful number, since it uses less digits than its factorization.

820028100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2733444 (or 2733437 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 820028100 is about 28636.1327696321. The cubic root of 820028100 is about 936.0008537869. Note that the first 3 decimals are identical.

Adding to 820028100 its reverse (1820028), we get a palindrome (821848128).

The spelling of 820028100 in words is "eight hundred twenty million, twenty-eight thousand, one hundred".