821752128000 has 1440 divisors, whose sum is σ = 3266651456640. Its totient is φ = 205584998400.

The previous prime is 821752127909. The next prime is 821752128011. The reversal of 821752128000 is 821257128.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 7978175949 + ... + 7978176051.

It is an arithmetic number, because the mean of its divisors is an integer number (2268507956).

Almost surely, 2^821752128000 is an apocalyptic number.

821752128000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821752128000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1633325728320).

821752128000 is an abundant number, since it is smaller than the sum of its proper divisors (2444899328640).

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

821752128000 is an frugal number, since it uses more digits than its factorization.

821752128000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The spelling of 821752128000 in words is "eight hundred twenty-one billion, seven hundred fifty-two million, one hundred twenty-eight thousand".