11991588 has 24 divisors (see below), whose sum is σ = 31977792. Its totient is φ = 3426144.

The previous prime is 11991583. The next prime is 11991601. The reversal of 11991588 is 88519911.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (11991583) 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 7 ways as a sum of consecutive naturals, for example, 71295 + ... + 71462.

It is an arithmetic number, because the mean of its divisors is an integer number (1332408).

Almost surely, 2^11991588 is an apocalyptic number.

It is an amenable number.

11991588 is an abundant number, since it is smaller than the sum of its proper divisors (19986204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11991588 is a wasteful number, since it uses less digits than its factorization.

11991588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142771 (or 142769 counting only the distinct ones).

The product of its digits is 25920, while the sum is 42.

The square root of 11991588 is about 3462.8872346642. The cubic root of 11991588 is about 228.8893396932.

The spelling of 11991588 in words is "eleven million, nine hundred ninety-one thousand, five hundred eighty-eight".