91608297840 has 560 divisors, whose sum is σ = 343492300800. Its totient is φ = 22637864448.

The previous prime is 91608297829. The next prime is 91608297883. The reversal of 91608297840 is 4879280619.

91608297840 is a `hidden beast` number, since 9 + 1 + 608 + 29 + 7 + 8 + 4 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 52078881 + ... + 52080639.

Almost surely, 2^91608297840 is an apocalyptic number.

91608297840 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 91608297840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171746150400).

91608297840 is an abundant number, since it is smaller than the sum of its proper divisors (251884002960).

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

91608297840 is a wasteful number, since it uses less digits than its factorization.

91608297840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1856 (or 1835 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 91608297840 in words is "ninety-one billion, six hundred eight million, two hundred ninety-seven thousand, eight hundred forty".