998996218920 has 512 divisors, whose sum is σ = 3968040960000. Its totient is φ = 218726065152.

The previous prime is 998996218879. The next prime is 998996218931. The reversal of 998996218920 is 29812699899.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 27825541 + ... + 27861419.

It is an arithmetic number, because the mean of its divisors is an integer number (7750080000).

Almost surely, 2^998996218920 is an apocalyptic number.

998996218920 is a gapful number since it is divisible by the number (90) 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 998996218920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1984020480000).

998996218920 is an abundant number, since it is smaller than the sum of its proper divisors (2969044741080).

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

998996218920 is a wasteful number, since it uses less digits than its factorization.

998996218920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36062 (or 36052 counting only the distinct ones).

The product of its (nonzero) digits is 90699264, while the sum is 72.

The spelling of 998996218920 in words is "nine hundred ninety-eight billion, nine hundred ninety-six million, two hundred eighteen thousand, nine hundred twenty".