11111421440 has 160 divisors (see below), whose sum is σ = 31772252160. Its totient is φ = 3643858944.

The previous prime is 11111421413. The next prime is 11111421479. The reversal of 11111421440 is 4412411111.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 398681 + ... + 425639.

It is an arithmetic number, because the mean of its divisors is an integer number (198576576).

Almost surely, 2^11111421440 is an apocalyptic number.

11111421440 is a gapful number since it is divisible by the number (10) 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 11111421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15886126080).

11111421440 is an abundant number, since it is smaller than the sum of its proper divisors (20660830720).

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

11111421440 is an equidigital number, since it uses as much as digits as its factorization.

11111421440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27012 (or 26996 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 11111421440 its reverse (4412411111), we get a palindrome (15523832551).

The spelling of 11111421440 in words is "eleven billion, one hundred eleven million, four hundred twenty-one thousand, four hundred forty".