11491209 has 12 divisors (see below), whose sum is σ = 16650036. Its totient is φ = 7636992.

The previous prime is 11491199. The next prime is 11491217. The reversal of 11491209 is 90219411.

It can be written as a sum of positive squares in 2 ways, for example, as 1587600 + 9903609 = 1260^2 + 3147^2 .

It is not a de Polignac number, because 11491209 - 2⁵ = 11491177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11491229) 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, 1369 + ... + 4985.

It is an arithmetic number, because the mean of its divisors is an integer number (1387503).

Almost surely, 2^11491209 is an apocalyptic number.

It is an amenable number.

11491209 is a deficient number, since it is larger than the sum of its proper divisors (5158827).

11491209 is a wasteful number, since it uses less digits than its factorization.

11491209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3976 (or 3973 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 11491209 is about 3389.8685815235. The cubic root of 11491209 is about 225.6603415811.

The spelling of 11491209 in words is "eleven million, four hundred ninety-one thousand, two hundred nine".