91403745840 has 320 divisors, whose sum is σ = 343810137600. Its totient is φ = 22135680000.

The previous prime is 91403745817. The next prime is 91403745847. The reversal of 91403745840 is 4854730419.

91403745840 is a `hidden beast` number, since 91 + 40 + 37 + 458 + 40 = 666.

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 (91403745847) 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, 40604715 + ... + 40606965.

It is an arithmetic number, because the mean of its divisors is an integer number (1074406680).

Almost surely, 2^91403745840 is an apocalyptic number.

91403745840 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 91403745840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171905068800).

91403745840 is an abundant number, since it is smaller than the sum of its proper divisors (252406391760).

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

91403745840 is a wasteful number, since it uses less digits than its factorization.

91403745840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3993 (or 3981 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 91403745840 in words is "ninety-one billion, four hundred three million, seven hundred forty-five thousand, eight hundred forty".