91081656 has 48 divisors (see below), whose sum is σ = 257409360. Its totient is φ = 29040000.

The previous prime is 91081651. The next prime is 91081673. The reversal of 91081656 is 65618019.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 91081656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91081651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25845 + ... + 29156.

It is an arithmetic number, because the mean of its divisors is an integer number (5362695).

Almost surely, 2^91081656 is an apocalyptic number.

It is an amenable number.

91081656 is an abundant number, since it is smaller than the sum of its proper divisors (166327704).

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

91081656 is a wasteful number, since it uses less digits than its factorization.

91081656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55036 (or 55029 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 91081656 is about 9543.6709918144. The cubic root of 91081656 is about 449.9286405365.

The spelling of 91081656 in words is "ninety-one million, eighty-one thousand, six hundred fifty-six".