21123222144440 has 64 divisors (see below), whose sum is σ = 51184263281760. Its totient is φ = 7799180336640.

The previous prime is 21123222144397. The next prime is 21123222144443. The reversal of 21123222144440 is 4444122232112.

It is a junction number, because it is equal to n+sod(n) for n = 21123222144397 and 21123222144406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123222144443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26027267 + ... + 26826573.

Almost surely, 2^{21123222144440} is an apocalyptic number.

21123222144440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21123222144440 is an abundant number, since it is smaller than the sum of its proper divisors (30061041137320).

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

21123222144440 is a wasteful number, since it uses less digits than its factorization.

21123222144440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850152 (or 850148 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 32.

Adding to 21123222144440 its reverse (4444122232112), we get a palindrome (25567344376552).

The spelling of 21123222144440 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred twenty-two million, one hundred forty-four thousand, four hundred forty".