91005379920 has 960 divisors, whose sum is σ = 389585064960. Its totient is φ = 18529026048.

The previous prime is 91005379919. The next prime is 91005379939. The reversal of 91005379920 is 2997350019.

It is a happy number.

91005379920 is a `hidden beast` number, since 9 + 1 + 0 + 0 + 537 + 99 + 20 = 666.

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

It is a zygodrome in base 3.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 253496701 + ... + 253497059.

It is an arithmetic number, because the mean of its divisors is an integer number (405817776).

Almost surely, 2^91005379920 is an apocalyptic number.

91005379920 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 91005379920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194792532480).

91005379920 is an abundant number, since it is smaller than the sum of its proper divisors (298579685040).

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

91005379920 is a wasteful number, since it uses less digits than its factorization.

91005379920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 153090, while the sum is 45.

The spelling of 91005379920 in words is "ninety-one billion, five million, three hundred seventy-nine thousand, nine hundred twenty".