990821710584 has 256 divisors, whose sum is σ = 2970855014400. Its totient is φ = 305077449600.

The previous prime is 990821710559. The next prime is 990821710591. The reversal of 990821710584 is 485017128099.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 990821710584.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 75611377 + ... + 75624479.

It is an arithmetic number, because the mean of its divisors is an integer number (11604902400).

Almost surely, 2^990821710584 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 990821710584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1485427507200).

990821710584 is an abundant number, since it is smaller than the sum of its proper divisors (1980033303816).

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

990821710584 is a wasteful number, since it uses less digits than its factorization.

990821710584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13663 (or 13653 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 990821710584 in words is "nine hundred ninety billion, eight hundred twenty-one million, seven hundred ten thousand, five hundred eighty-four".