11661191 has 4 divisors (see below), whose sum is σ = 11674800. Its totient is φ = 11647584.

The previous prime is 11661163. The next prime is 11661197. The reversal of 11661191 is 19116611.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11661191 - 2¹⁴ = 11644807 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11661191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11661197) 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, 5426 + ... + 7263.

It is an arithmetic number, because the mean of its divisors is an integer number (2918700).

Almost surely, 2^11661191 is an apocalyptic number.

11661191 is a deficient number, since it is larger than the sum of its proper divisors (13609).

11661191 is an equidigital number, since it uses as much as digits as its factorization.

11661191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13608.

The product of its digits is 324, while the sum is 26.

The square root of 11661191 is about 3414.8486057218. The cubic root of 11661191 is about 226.7675821788.

It can be divided in two parts, 116611 and 91, that multiplied together give a palindrome (10611601).

The spelling of 11661191 in words is "eleven million, six hundred sixty-one thousand, one hundred ninety-one".