21444324020 has 24 divisors (see below), whose sum is σ = 51466377984. Its totient is φ = 7352339616.

The previous prime is 21444324019. The next prime is 21444324023. The reversal of 21444324020 is 2042344412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444324023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76586732 + ... + 76587011.

It is an arithmetic number, because the mean of its divisors is an integer number (2144432416).

Almost surely, 2^21444324020 is an apocalyptic number.

21444324020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21444324020 is an abundant number, since it is smaller than the sum of its proper divisors (30022053964).

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

21444324020 is a wasteful number, since it uses less digits than its factorization.

21444324020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153173759 (or 153173757 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21444324020 its reverse (2042344412), we get a palindrome (23486668432).

The spelling of 21444324020 in words is "twenty-one billion, four hundred forty-four million, three hundred twenty-four thousand, twenty".