91684016640 has 480 divisors, whose sum is σ = 346663437120. Its totient is φ = 23159291904.

The previous prime is 91684016587. The next prime is 91684016741. The reversal of 91684016640 is 4661048619.

91684016640 is a `hidden beast` number, since 91 + 68 + 401 + 66 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11815642 + ... + 11823398.

It is an arithmetic number, because the mean of its divisors is an integer number (722215494).

Almost surely, 2^91684016640 is an apocalyptic number.

91684016640 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 91684016640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (173331718560).

91684016640 is an abundant number, since it is smaller than the sum of its proper divisors (254979420480).

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

91684016640 is an equidigital number, since it uses as much as digits as its factorization.

91684016640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7814 (or 7786 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 91684016640 in words is "ninety-one billion, six hundred eighty-four million, sixteen thousand, six hundred forty".