91691186400 has 1296 divisors, whose sum is σ = 388027602144. Its totient is φ = 20275200000.

The previous prime is 91691186399. The next prime is 91691186407. The reversal of 91691186400 is 468119619.

91691186400 is a `hidden beast` number, since 9 + 1 + 69 + 1 + 186 + 400 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91691186407) by changing a digit.

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 215 ways as a sum of consecutive naturals, for example, 607226325 + ... + 607226475.

It is an arithmetic number, because the mean of its divisors is an integer number (299404014).

Almost surely, 2^91691186400 is an apocalyptic number.

91691186400 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 91691186400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194013801072).

91691186400 is an abundant number, since it is smaller than the sum of its proper divisors (296336415744).

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

91691186400 is a wasteful number, since it uses less digits than its factorization.

91691186400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 91691186400 in words is "ninety-one billion, six hundred ninety-one million, one hundred eighty-six thousand, four hundred".