91390209 has 8 divisors (see below), whose sum is σ = 128267040. Its totient is φ = 57720096.

The previous prime is 91390177. The next prime is 91390213. The reversal of 91390209 is 90209319.

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

It is not a de Polignac number, because 91390209 - 2⁵ = 91390177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91390209.

It is not an unprimeable number, because it can be changed into a prime (91390009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 801612 + ... + 801725.

It is an arithmetic number, because the mean of its divisors is an integer number (16033380).

Almost surely, 2^91390209 is an apocalyptic number.

It is an amenable number.

91390209 is a deficient number, since it is larger than the sum of its proper divisors (36876831).

91390209 is a wasteful number, since it uses less digits than its factorization.

91390209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603359.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 91390209 is about 9559.8226447984. The cubic root of 91390209 is about 450.4361351906.

The spelling of 91390209 in words is "ninety-one million, three hundred ninety thousand, two hundred nine".