91120304640 has 320 divisors, whose sum is σ = 310716362880. Its totient is φ = 22700359680.

The previous prime is 91120304617. The next prime is 91120304647. The reversal of 91120304640 is 4640302119.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 91120304598 and 91120304607.

It is not an unprimeable number, because it can be changed into a prime (91120304647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18145330 + ... + 18150350.

It is an arithmetic number, because the mean of its divisors is an integer number (970988634).

Almost surely, 2^91120304640 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 91120304640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155358181440).

91120304640 is an abundant number, since it is smaller than the sum of its proper divisors (219596058240).

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

91120304640 is a wasteful number, since it uses less digits than its factorization.

91120304640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5203 (or 5187 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

Adding to 91120304640 its reverse (4640302119), we get a palindrome (95760606759).

The spelling of 91120304640 in words is "ninety-one billion, one hundred twenty million, three hundred four thousand, six hundred forty".