11688991 has 16 divisors (see below), whose sum is σ = 12773376. Its totient is φ = 10666656.

The previous prime is 11688983. The next prime is 11689039. The reversal of 11688991 is 19988611.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 11688991 - 2³ = 11688983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11688961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52306 + ... + 52528.

It is an arithmetic number, because the mean of its divisors is an integer number (798336).

Almost surely, 2^11688991 is an apocalyptic number.

11688991 is a deficient number, since it is larger than the sum of its proper divisors (1084385).

11688991 is a wasteful number, since it uses less digits than its factorization.

11688991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342.

The product of its digits is 31104, while the sum is 43.

The square root of 11688991 is about 3418.9166412769. The cubic root of 11688991 is about 226.9476419963.

The spelling of 11688991 in words is "eleven million, six hundred eighty-eight thousand, nine hundred ninety-one".