11659991 has 6 divisors (see below), whose sum is σ = 13563720. Its totient is φ = 9994236.

The previous prime is 11659987. The next prime is 11660003. The reversal of 11659991 is 19995611.

It is not a de Polignac number, because 11659991 - 2² = 11659987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11659951) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 118931 + ... + 119028.

It is an arithmetic number, because the mean of its divisors is an integer number (2260620).

Almost surely, 2^11659991 is an apocalyptic number.

11659991 is a deficient number, since it is larger than the sum of its proper divisors (1903729).

11659991 is an equidigital number, since it uses as much as digits as its factorization.

11659991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237973 (or 237966 counting only the distinct ones).

The product of its digits is 21870, while the sum is 41.

The square root of 11659991 is about 3414.6728979508. The cubic root of 11659991 is about 226.7598033726.

The spelling of 11659991 in words is "eleven million, six hundred fifty-nine thousand, nine hundred ninety-one".