21404223144 has 96 divisors (see below), whose sum is σ = 58995331200. Its totient is φ = 7008819840.

The previous prime is 21404223119. The next prime is 21404223149. The reversal of 21404223144 is 44132240412.

21404223144 is a `hidden beast` number, since 21 + 404 + 2 + 231 + 4 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (21404223149) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4033597 + ... + 4038899.

It is an arithmetic number, because the mean of its divisors is an integer number (614534700).

Almost surely, 2^21404223144 is an apocalyptic number.

21404223144 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 21404223144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29497665600).

21404223144 is an abundant number, since it is smaller than the sum of its proper divisors (37591108056).

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

21404223144 is a wasteful number, since it uses less digits than its factorization.

21404223144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6295 (or 6288 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

Adding to 21404223144 its reverse (44132240412), we get a palindrome (65536463556).

The spelling of 21404223144 in words is "twenty-one billion, four hundred four million, two hundred twenty-three thousand, one hundred forty-four".