21444424444 has 12 divisors (see below), whose sum is σ = 39735257184. Its totient is φ = 10091493824.

The previous prime is 21444424411. The next prime is 21444424481. The reversal of 21444424444 is 44442444412.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157679524 + ... + 157679659.

It is an arithmetic number, because the mean of its divisors is an integer number (3311271432).

Almost surely, 2^21444424444 is an apocalyptic number.

It is an amenable number.

21444424444 is a deficient number, since it is larger than the sum of its proper divisors (18290832740).

21444424444 is a wasteful number, since it uses less digits than its factorization.

21444424444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315359204 (or 315359202 counting only the distinct ones).

The product of its digits is 262144, while the sum is 37.

Adding to 21444424444 its reverse (44442444412), we get a palindrome (65886868856).

The spelling of 21444424444 in words is "twenty-one billion, four hundred forty-four million, four hundred twenty-four thousand, four hundred forty-four".