91681136 has 80 divisors (see below), whose sum is σ = 197987328. Its totient is φ = 40934400.

The previous prime is 91681111. The next prime is 91681141. The reversal of 91681136 is 63118619.

It is a junction number, because it is equal to n+sod(n) for n = 91681096 and 91681105.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 699791 + ... + 699921.

Almost surely, 2^91681136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91681136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98993664).

91681136 is an abundant number, since it is smaller than the sum of its proper divisors (106306192).

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

91681136 is a wasteful number, since it uses less digits than its factorization.

91681136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270 (or 264 counting only the distinct ones).

The product of its digits is 7776, while the sum is 35.

The square root of 91681136 is about 9575.0266840359. The cubic root of 91681136 is about 450.9135941632.

The spelling of 91681136 in words is "ninety-one million, six hundred eighty-one thousand, one hundred thirty-six".