21112012221144 has 128 divisors (see below), whose sum is σ = 60203597690880. Its totient is φ = 6111850752000.

The previous prime is 21112012221143. The next prime is 21112012221149. The reversal of 21112012221144 is 44112221021112.

It is a super-2 number, since 2×21112012221144² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112012221143) 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, 15309369 + ... + 16631319.

It is an arithmetic number, because the mean of its divisors is an integer number (470340606960).

Almost surely, 2^{21112012221144} is an apocalyptic number.

21112012221144 is a gapful number since it is divisible by the number (24) 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 21112012221144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30101798845440).

21112012221144 is an abundant number, since it is smaller than the sum of its proper divisors (39091585469736).

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

21112012221144 is a wasteful number, since it uses less digits than its factorization.

21112012221144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325001 (or 1324997 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

Adding to 21112012221144 its reverse (44112221021112), we get a palindrome (65224233242256).

The spelling of 21112012221144 in words is "twenty-one trillion, one hundred twelve billion, twelve million, two hundred twenty-one thousand, one hundred forty-four".