91591245756720 has 320 divisors, whose sum is σ = 319971620505600. Its totient is φ = 24077630453760.

The previous prime is 91591245756707. The next prime is 91591245756721. The reversal of 91591245756720 is 2765754219519.

It is a happy number.

91591245756720 is a `hidden beast` number, since 9 + 1 + 5 + 9 + 1 + 2 + 45 + 7 + 567 + 20 = 666.

It is not an unprimeable number, because it can be changed into a prime (91591245756721) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 109304140 + ... + 110138900.

It is an arithmetic number, because the mean of its divisors is an integer number (999911314080).

Almost surely, 2^{91591245756720} is an apocalyptic number.

91591245756720 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 91591245756720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159985810252800).

91591245756720 is an abundant number, since it is smaller than the sum of its proper divisors (228380374748880).

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

91591245756720 is a wasteful number, since it uses less digits than its factorization.

91591245756720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835505 (or 835493 counting only the distinct ones).

The product of its (nonzero) digits is 47628000, while the sum is 63.

The spelling of 91591245756720 in words is "ninety-one trillion, five hundred ninety-one billion, two hundred forty-five million, seven hundred fifty-six thousand, seven hundred twenty".