21012244224 has 36 divisors (see below), whose sum is σ = 55923214536. Its totient is φ = 7004081152.

The previous prime is 21012244223. The next prime is 21012244289. The reversal of 21012244224 is 42244221012.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21012244194 and 21012244203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012244223) 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, 13679079 + ... + 13680614.

It is an arithmetic number, because the mean of its divisors is an integer number (1553422626).

Almost surely, 2^21012244224 is an apocalyptic number.

21012244224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21012244224 is an abundant number, since it is smaller than the sum of its proper divisors (34910970312).

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

21012244224 is an equidigital number, since it uses as much as digits as its factorization.

21012244224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27359712 (or 27359698 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

Adding to 21012244224 its reverse (42244221012), we get a palindrome (63256465236).

The spelling of 21012244224 in words is "twenty-one billion, twelve million, two hundred forty-four thousand, two hundred twenty-four".