990690221808 has 360 divisors, whose sum is σ = 3292399616688. Its totient is φ = 277179162624.

The previous prime is 990690221797. The next prime is 990690221813. The reversal of 990690221808 is 808122096099.

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 71 ways as a sum of consecutive naturals, for example, 219516960 + ... + 219521472.

Almost surely, 2^990690221808 is an apocalyptic number.

990690221808 is a gapful number since it is divisible by the number (98) 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 990690221808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1646199808344).

990690221808 is an abundant number, since it is smaller than the sum of its proper divisors (2301709394880).

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

990690221808 is a wasteful number, since it uses less digits than its factorization.

990690221808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5181 (or 5165 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 990690221808 in words is "nine hundred ninety billion, six hundred ninety million, two hundred twenty-one thousand, eight hundred eight".