91158963840 has 512 divisors, whose sum is σ = 370419609600. Its totient is φ = 20754911232.

The previous prime is 91158963811. The next prime is 91158963877. The reversal of 91158963840 is 4836985119.

91158963840 is a `hidden beast` number, since 9 + 11 + 589 + 6 + 3 + 8 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 34230349 + ... + 34233011.

It is an arithmetic number, because the mean of its divisors is an integer number (723475800).

Almost surely, 2^91158963840 is an apocalyptic number.

91158963840 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 91158963840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185209804800).

91158963840 is an abundant number, since it is smaller than the sum of its proper divisors (279260645760).

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

91158963840 is a wasteful number, since it uses less digits than its factorization.

91158963840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2981 (or 2963 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The spelling of 91158963840 in words is "ninety-one billion, one hundred fifty-eight million, nine hundred sixty-three thousand, eight hundred forty".