9391121659920 has 640 divisors, whose sum is σ = 39885847142400. Its totient is φ = 1801291806720.

The previous prime is 9391121659877. The next prime is 9391121659921. The reversal of 9391121659920 is 299561211939.

It is a super-2 number, since 2×9391121659920² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9391121659921) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 11372877 + ... + 12170643.

It is an arithmetic number, because the mean of its divisors is an integer number (62321636160).

Almost surely, 2^{9391121659920} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9391121659920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19942923571200).

9391121659920 is an abundant number, since it is smaller than the sum of its proper divisors (30494725482480).

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

9391121659920 is a wasteful number, since it uses less digits than its factorization.

9391121659920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797828 (or 797808 counting only the distinct ones).

The product of its (nonzero) digits is 2361960, while the sum is 57.

The spelling of 9391121659920 in words is "nine trillion, three hundred ninety-one billion, one hundred twenty-one million, six hundred fifty-nine thousand, nine hundred twenty".