21444311420 has 48 divisors (see below), whose sum is σ = 52117847040. Its totient is φ = 7259264064.

The previous prime is 21444311389. The next prime is 21444311423. The reversal of 21444311420 is 2411344412.

It is a self number, because there is not a number n which added to its sum of digits gives 21444311420.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444311423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 958394 + ... + 980513.

It is an arithmetic number, because the mean of its divisors is an integer number (1085788480).

Almost surely, 2^21444311420 is an apocalyptic number.

21444311420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21444311420 is an abundant number, since it is smaller than the sum of its proper divisors (30673535620).

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

21444311420 is a wasteful number, since it uses less digits than its factorization.

21444311420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939002 (or 1939000 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

Adding to 21444311420 its reverse (2411344412), we get a palindrome (23855655832).

The spelling of 21444311420 in words is "twenty-one billion, four hundred forty-four million, three hundred eleven thousand, four hundred twenty".