91081563 has 8 divisors (see below), whose sum is σ = 128585808. Its totient is φ = 57149184.

The previous prime is 91081519. The next prime is 91081567. The reversal of 91081563 is 36518019.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91081563 - 2⁶ = 91081499 is a prime.

It is a super-2 number, since 2×91081563² = 16591702237045938, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91081567) 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 7 ways as a sum of consecutive naturals, for example, 892906 + ... + 893007.

It is an arithmetic number, because the mean of its divisors is an integer number (16073226).

Almost surely, 2^91081563 is an apocalyptic number.

91081563 is a deficient number, since it is larger than the sum of its proper divisors (37504245).

91081563 is a wasteful number, since it uses less digits than its factorization.

91081563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785933.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 91081563 is about 9543.6661194742. Note that the first 3 decimals coincide. The cubic root of 91081563 is about 449.9284874015.

The spelling of 91081563 in words is "ninety-one million, eighty-one thousand, five hundred sixty-three".