9817920 has 168 divisors, whose sum is σ = 38673024. Its totient is φ = 2239488.

The previous prime is 9817919. The next prime is 9817931. The reversal of 9817920 is 297189.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (168).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19917 + ... + 20403.

Almost surely, 2^9817920 is an apocalyptic number.

9817920 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 9817920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19336512).

9817920 is an abundant number, since it is smaller than the sum of its proper divisors (28855104).

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

9817920 is a wasteful number, since it uses less digits than its factorization.

9817920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 504 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 9817920 is about 3133.3560282866. The cubic root of 9817920 is about 214.1278532585.

The spelling of 9817920 in words is "nine million, eight hundred seventeen thousand, nine hundred twenty".