11991489 has 16 divisors (see below), whose sum is σ = 17049600. Its totient is φ = 7474896.

The previous prime is 11991481. The next prime is 11991517. The reversal of 11991489 is 98419911.

It is a happy number.

It is not a de Polignac number, because 11991489 - 2³ = 11991481 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11991489.

It is not an unprimeable number, because it can be changed into a prime (11991481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3172 + ... + 5834.

It is an arithmetic number, because the mean of its divisors is an integer number (1065600).

Almost surely, 2^11991489 is an apocalyptic number.

11991489 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

11991489 is a deficient number, since it is larger than the sum of its proper divisors (5058111).

11991489 is a wasteful number, since it uses less digits than its factorization.

11991489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2764.

The product of its digits is 23328, while the sum is 42.

The square root of 11991489 is about 3462.8729402044. The cubic root of 11991489 is about 228.8887098043. Note that the first 3 decimals are identical.

The spelling of 11991489 in words is "eleven million, nine hundred ninety-one thousand, four hundred eighty-nine".