821011020110128 has 80 divisors (see below), whose sum is σ = 1669184496069120. Its totient is φ = 390454149076992.

The previous prime is 821011020110123. The next prime is 821011020110213.

821011020110128 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 821011020110096 and 821011020110105.

It is not an unprimeable number, because it can be changed into a prime (821011020110123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3142820125 + ... + 3143081347.

It is an arithmetic number, because the mean of its divisors is an integer number (20864806200864).

Almost surely, 2^{821011020110128} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821011020110128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834592248034560).

821011020110128 is an abundant number, since it is smaller than the sum of its proper divisors (848173475958992).

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

821011020110128 is a wasteful number, since it uses less digits than its factorization.

821011020110128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309146 (or 309140 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 28.

The spelling of 821011020110128 in words is "eight hundred twenty-one trillion, eleven billion, twenty million, one hundred ten thousand, one hundred twenty-eight".