11965691 has 4 divisors (see below), whose sum is σ = 11973312. Its totient is φ = 11958072.

The previous prime is 11965673. The next prime is 11965697. The reversal of 11965691 is 19656911.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 19656911 = 421 ⋅46691.

It is a cyclic number.

It is not a de Polignac number, because 11965691 - 2⁶ = 11965627 is a prime.

It is a super-2 number, since 2×11965691² = 286355522214962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11965697) 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, 491 + ... + 4916.

It is an arithmetic number, because the mean of its divisors is an integer number (2993328).

Almost surely, 2^11965691 is an apocalyptic number.

11965691 is a deficient number, since it is larger than the sum of its proper divisors (7621).

11965691 is an equidigital number, since it uses as much as digits as its factorization.

11965691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7620.

The product of its digits is 14580, while the sum is 38.

The square root of 11965691 is about 3459.1459928717. The cubic root of 11965691 is about 228.7244513455.

It can be divided in two parts, 11 and 965691, that multiplied together give a palindrome (10622601).

The spelling of 11965691 in words is "eleven million, nine hundred sixty-five thousand, six hundred ninety-one".