91911009 has 4 divisors (see below), whose sum is σ = 122548016. Its totient is φ = 61274004.

The previous prime is 91911007. The next prime is 91911047. The reversal of 91911009 is 90011919.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 91911009 - 2¹ = 91911007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91911007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15318499 + ... + 15318504.

It is an arithmetic number, because the mean of its divisors is an integer number (30637004).

Almost surely, 2^91911009 is an apocalyptic number.

It is an amenable number.

91911009 is a deficient number, since it is larger than the sum of its proper divisors (30637007).

91911009 is a wasteful number, since it uses less digits than its factorization.

91911009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30637006.

The product of its (nonzero) digits is 729, while the sum is 30.

The square root of 91911009 is about 9587.0229477143. The cubic root of 91911009 is about 451.2901396399.

The spelling of 91911009 in words is "ninety-one million, nine hundred eleven thousand, nine".