11981844 has 84 divisors (see below), whose sum is σ = 35990304. Its totient is φ = 3417552.

The previous prime is 11981839. The next prime is 11981863. The reversal of 11981844 is 44818911.

It is a tau number, because it is divible by the number of its divisors (84).

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

It is a junction number, because it is equal to n+sod(n) for n = 11981799 and 11981808.

It is a congruent number.

It is an unprimeable number.

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 27 ways as a sum of consecutive naturals, for example, 20119 + ... + 20705.

It is an arithmetic number, because the mean of its divisors is an integer number (428456).

Almost surely, 2^11981844 is an apocalyptic number.

11981844 is a gapful number since it is divisible by the number (14) 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 11981844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17995152).

11981844 is an abundant number, since it is smaller than the sum of its proper divisors (24008460).

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

11981844 is an equidigital number, since it uses as much as digits as its factorization.

11981844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616 (or 599 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 11981844 is about 3461.4800302761. The cubic root of 11981844 is about 228.8273267196.

The spelling of 11981844 in words is "eleven million, nine hundred eighty-one thousand, eight hundred forty-four".