91597251240 has 768 divisors, whose sum is σ = 356476723200. Its totient is φ = 20151244800.

The previous prime is 91597251199. The next prime is 91597251257. The reversal of 91597251240 is 4215279519.

91597251240 is a `hidden beast` number, since 9 + 1 + 5 + 97 + 2 + 512 + 40 = 666.

It is a super-3 number, since 3×91597251240³ (a number of 34 digits) contains 333 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 403512007 + ... + 403512233.

It is an arithmetic number, because the mean of its divisors is an integer number (464162400).

Almost surely, 2^91597251240 is an apocalyptic number.

91597251240 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 91597251240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178238361600).

91597251240 is an abundant number, since it is smaller than the sum of its proper divisors (264879471960).

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

91597251240 is a wasteful number, since it uses less digits than its factorization.

91597251240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The spelling of 91597251240 in words is "ninety-one billion, five hundred ninety-seven million, two hundred fifty-one thousand, two hundred forty".