91081206 has 64 divisors (see below), whose sum is σ = 218972160. Its totient is φ = 27953280.

The previous prime is 91081169. The next prime is 91081217. The reversal of 91081206 is 60218019.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 91081206.

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 31 ways as a sum of consecutive naturals, for example, 42091 + ... + 44201.

It is an arithmetic number, because the mean of its divisors is an integer number (3421440).

Almost surely, 2^91081206 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91081206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109486080).

91081206 is an abundant number, since it is smaller than the sum of its proper divisors (127890954).

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

91081206 is a wasteful number, since it uses less digits than its factorization.

91081206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2186 (or 2180 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 91081206 is about 9543.6474159516. The cubic root of 91081206 is about 449.9278995596.

The spelling of 91081206 in words is "ninety-one million, eighty-one thousand, two hundred six".