9918097920 has 640 divisors, whose sum is σ = 37334753280. Its totient is φ = 2492743680.

The previous prime is 9918097883. The next prime is 9918097951. The reversal of 9918097920 is 297908199.

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

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 63 ways as a sum of consecutive naturals, for example, 139691485 + ... + 139691555.

It is an arithmetic number, because the mean of its divisors is an integer number (58335552).

Almost surely, 2^9918097920 is an apocalyptic number.

9918097920 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 9918097920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18667376640).

9918097920 is an abundant number, since it is smaller than the sum of its proper divisors (27416655360).

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

9918097920 is a wasteful number, since it uses less digits than its factorization.

9918097920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193 (or 171 counting only the distinct ones).

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

The square root of 9918097920 is about 99589.6476547638. The cubic root of 9918097920 is about 2148.5368028868.

The spelling of 9918097920 in words is "nine billion, nine hundred eighteen million, ninety-seven thousand, nine hundred twenty".