821573012880 has 480 divisors, whose sum is σ = 2841023877120. Its totient is φ = 212695372800.

The previous prime is 821573012831. The next prime is 821573012903. The reversal of 821573012880 is 88210375128.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1687007997 + ... + 1687008483.

It is an arithmetic number, because the mean of its divisors is an integer number (5918799744).

Almost surely, 2^821573012880 is an apocalyptic number.

821573012880 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 821573012880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1420511938560).

821573012880 is an abundant number, since it is smaller than the sum of its proper divisors (2019450864240).

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

821573012880 is a wasteful number, since it uses less digits than its factorization.

821573012880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 821573012880 in words is "eight hundred twenty-one billion, five hundred seventy-three million, twelve thousand, eight hundred eighty".