91247563440 has 240 divisors, whose sum is σ = 341412005376. Its totient is φ = 21649881600.

The previous prime is 91247563411. The next prime is 91247563447. The reversal of 91247563440 is 4436574219.

91247563440 is a `hidden beast` number, since 9 + 1 + 2 + 4 + 7 + 5 + 634 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×91247563440² (a number of 23 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (91247563447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 249675 + ... + 494805.

Almost surely, 2^91247563440 is an apocalyptic number.

91247563440 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 91247563440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170706002688).

91247563440 is an abundant number, since it is smaller than the sum of its proper divisors (250164441936).

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

91247563440 is a wasteful number, since it uses less digits than its factorization.

91247563440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245208 (or 245199 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 91247563440 in words is "ninety-one billion, two hundred forty-seven million, five hundred sixty-three thousand, four hundred forty".