111981636 has 96 divisors (see below), whose sum is σ = 319495680. Its totient is φ = 33702912.

The previous prime is 111981613. The next prime is 111981637. The reversal of 111981636 is 636189111.

It is a happy number.

111981636 is a `hidden beast` number, since 1 + 1 + 19 + 8 + 1 + 636 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 111981636.

It is not an unprimeable number, because it can be changed into a prime (111981637) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65140 + ... + 66836.

It is an arithmetic number, because the mean of its divisors is an integer number (3328080).

Almost surely, 2^111981636 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 111981636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159747840).

111981636 is an abundant number, since it is smaller than the sum of its proper divisors (207514044).

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

111981636 is a wasteful number, since it uses less digits than its factorization.

111981636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1770 (or 1762 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 111981636 is about 10582.1375912431. The cubic root of 111981636 is about 482.0021062447.

The spelling of 111981636 in words is "one hundred eleven million, nine hundred eighty-one thousand, six hundred thirty-six".