21444444444444 has 36 divisors (see below), whose sum is σ = 58206349207944. Its totient is φ = 6126984126816.

The previous prime is 21444444444439. The next prime is 21444444444509. The reversal of 21444444444444 is 44444444444412.

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

21444444444444 is a modest number, since divided by 4444444 gives 2144444 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18235071219 + ... + 18235072394.

It is an arithmetic number, because the mean of its divisors is an integer number (1616843033554).

Almost surely, 2^{21444444444444} is an apocalyptic number.

It is an amenable number.

21444444444444 is an abundant number, since it is smaller than the sum of its proper divisors (36761904763500).

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

21444444444444 is a wasteful number, since it uses less digits than its factorization.

21444444444444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36470143634 (or 36470143625 counting only the distinct ones).

The product of its digits is 33554432, while the sum is 51.

Adding to 21444444444444 its reverse (44444444444412), we get a palindrome (65888888888856).

The spelling of 21444444444444 in words is "twenty-one trillion, four hundred forty-four billion, four hundred forty-four million, four hundred forty-four thousand, four hundred forty-four".