21144242224 has 20 divisors (see below), whose sum is σ = 46819393744. Its totient is φ = 9061818048.

The previous prime is 21144242191. The next prime is 21144242227. The reversal of 21144242224 is 42224244112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21144242192 and 21144242201.

It is not an unprimeable number, because it can be changed into a prime (21144242227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94393827 + ... + 94394050.

Almost surely, 2^21144242224 is an apocalyptic number.

It is an amenable number.

21144242224 is an abundant number, since it is smaller than the sum of its proper divisors (25675151520).

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

21144242224 is a wasteful number, since it uses less digits than its factorization.

21144242224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188787892 (or 188787886 counting only the distinct ones).

The product of its digits is 8192, while the sum is 28.

Adding to 21144242224 its reverse (42224244112), we get a palindrome (63368486336).

The spelling of 21144242224 in words is "twenty-one billion, one hundred forty-four million, two hundred forty-two thousand, two hundred twenty-four".