91005005 has 24 divisors (see below), whose sum is σ = 136812312. Its totient is φ = 57601152.

The previous prime is 91004999. The next prime is 91005007. The reversal of 91005005 is 50050019.

It can be written as a sum of positive squares in 4 ways, for example, as 5368489 + 85636516 = 2317^2 + 9254^2 .

It is not a de Polignac number, because 91005005 - 2⁴ = 91004989 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91005007) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11102 + ... + 17471.

It is an arithmetic number, because the mean of its divisors is an integer number (5700513).

Almost surely, 2^91005005 is an apocalyptic number.

It is an amenable number.

91005005 is a deficient number, since it is larger than the sum of its proper divisors (45807307).

91005005 is a wasteful number, since it uses less digits than its factorization.

91005005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28605 (or 28598 counting only the distinct ones).

The product of its (nonzero) digits is 225, while the sum is 20.

The square root of 91005005 is about 9539.6543438429. The cubic root of 91005005 is about 449.8023906023.

The spelling of 91005005 in words is "ninety-one million, five thousand, five".