11991888 has 100 divisors (see below), whose sum is σ = 36609760. Its totient is φ = 3779136.

The previous prime is 11991839. The next prime is 11991911. The reversal of 11991888 is 88819911.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24381 + ... + 24867.

Almost surely, 2^11991888 is an apocalyptic number.

11991888 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11991888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18304880).

11991888 is an abundant number, since it is smaller than the sum of its proper divisors (24617872).

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

11991888 is a wasteful number, since it uses less digits than its factorization.

11991888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526 (or 511 counting only the distinct ones).

The product of its digits is 41472, while the sum is 45.

The square root of 11991888 is about 3462.9305508485. The cubic root of 11991888 is about 228.8912484265.

The spelling of 11991888 in words is "eleven million, nine hundred ninety-one thousand, eight hundred eighty-eight".