9998017920 has 640 divisors, whose sum is σ = 39588199200. Its totient is φ = 2384363520.

The previous prime is 9998017871. The next prime is 9998017961. The reversal of 9998017920 is 297108999.

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×9998017920² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 50751262 + ... + 50751458.

Almost surely, 2^9998017920 is an apocalyptic number.

9998017920 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 9998017920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19794099600).

9998017920 is an abundant number, since it is smaller than the sum of its proper divisors (29590181280).

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

9998017920 is a wasteful number, since it uses less digits than its factorization.

9998017920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 734832, while the sum is 54.

The square root of 9998017920 is about 99990.0891088712. The cubic root of 9998017920 is about 2154.2923385627.

The spelling of 9998017920 in words is "nine billion, nine hundred ninety-eight million, seventeen thousand, nine hundred twenty".