91040785920 has 1280 divisors, whose sum is σ = 394277621760. Its totient is φ = 19707494400.

The previous prime is 91040785919. The next prime is 91040785949. The reversal of 91040785920 is 2958704019.

91040785920 is a `hidden beast` number, since 9 + 10 + 40 + 7 + 8 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

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 127 ways as a sum of consecutive naturals, for example, 901393870 + ... + 901393970.

It is an arithmetic number, because the mean of its divisors is an integer number (308029392).

Almost surely, 2^91040785920 is an apocalyptic number.

91040785920 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 91040785920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197138810880).

91040785920 is an abundant number, since it is smaller than the sum of its proper divisors (303236835840).

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

91040785920 is an equidigital number, since it uses as much as digits as its factorization.

91040785920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 91040785920 in words is "ninety-one billion, forty million, seven hundred eighty-five thousand, nine hundred twenty".