21344420020 has 96 divisors (see below), whose sum is σ = 55929968640. Its totient is φ = 6647283840.

The previous prime is 21344420017. The next prime is 21344420039. The reversal of 21344420020 is 2002444312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21344419973 and 21344420000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2100111 + ... + 2110249.

It is an arithmetic number, because the mean of its divisors is an integer number (582603840).

Almost surely, 2^21344420020 is an apocalyptic number.

21344420020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21344420020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27964984320).

21344420020 is an abundant number, since it is smaller than the sum of its proper divisors (34585548620).

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

21344420020 is a wasteful number, since it uses less digits than its factorization.

21344420020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11533 (or 11531 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21344420020 its reverse (2002444312), we get a palindrome (23346864332).

The spelling of 21344420020 in words is "twenty-one billion, three hundred forty-four million, four hundred twenty thousand, twenty".