11111988 has 48 divisors (see below), whose sum is σ = 27578880. Its totient is φ = 3475584.

The previous prime is 11111983. The next prime is 11111993. The reversal of 11111988 is 88911111.

It is an interprime number because it is at equal distance from previous prime (11111983) and next prime (11111993).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12445 + ... + 13307.

It is an arithmetic number, because the mean of its divisors is an integer number (574560).

Almost surely, 2^11111988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11111988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13789440).

11111988 is an abundant number, since it is smaller than the sum of its proper divisors (16466892).

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

11111988 is a wasteful number, since it uses less digits than its factorization.

11111988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936 (or 934 counting only the distinct ones).

The product of its digits is 576, while the sum is 30.

The square root of 11111988 is about 3333.4648640716. The cubic root of 11111988 is about 223.1501867228.

The spelling of 11111988 in words is "eleven million, one hundred eleven thousand, nine hundred eighty-eight".