821000128 has 28 divisors (see below), whose sum is σ = 1754494840. Its totient is φ = 378922752.

The previous prime is 821000119. The next prime is 821000129.

821000128 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 821000099 and 821000108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821000129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 492558 + ... + 494221.

It is an arithmetic number, because the mean of its divisors is an integer number (62660530).

Almost surely, 2^821000128 is an apocalyptic number.

It is an amenable number.

821000128 is an abundant number, since it is smaller than the sum of its proper divisors (933494712).

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

821000128 is a wasteful number, since it uses less digits than its factorization.

821000128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986804 (or 986794 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 821000128 is about 28653.0997974041. The cubic root of 821000128 is about 936.3705402188.

It can be divided in two parts, 821000 and 128, that added together give a palindrome (821128).

The spelling of 821000128 in words is "eight hundred twenty-one million, one hundred twenty-eight", and thus it is an aban number.