11665989 has 24 divisors (see below), whose sum is σ = 17659512. Its totient is φ = 7413120.

The previous prime is 11665963. The next prime is 11666021. The reversal of 11665989 is 98956611.

It can be written as a sum of positive squares in 4 ways, for example, as 7064964 + 4601025 = 2658^2 + 2145^2 .

It is not a de Polignac number, because 11665989 - 2⁷ = 11665861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11665189) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17319 + ... + 17979.

It is an arithmetic number, because the mean of its divisors is an integer number (735813).

Almost surely, 2^11665989 is an apocalyptic number.

It is an amenable number.

11665989 is a deficient number, since it is larger than the sum of its proper divisors (5993523).

11665989 is a wasteful number, since it uses less digits than its factorization.

11665989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757 (or 754 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 11665989 is about 3415.5510536369. The cubic root of 11665989 is about 226.7986791073.

The spelling of 11665989 in words is "eleven million, six hundred sixty-five thousand, nine hundred eighty-nine".