21313424420 has 96 divisors (see below), whose sum is σ = 49821004800. Its totient is φ = 7625318400.

The previous prime is 21313424413. The next prime is 21313424449. The reversal of 21313424420 is 2442431312.

It is a self number, because there is not a number n which added to its sum of digits gives 21313424420.

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, 460916 + ... + 505044.

It is an arithmetic number, because the mean of its divisors is an integer number (518968800).

Almost surely, 2^21313424420 is an apocalyptic number.

21313424420 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 21313424420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24910502400).

21313424420 is an abundant number, since it is smaller than the sum of its proper divisors (28507580380).

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

21313424420 is a wasteful number, since it uses less digits than its factorization.

21313424420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44229 (or 44227 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21313424420 its reverse (2442431312), we get a palindrome (23755855732).

The spelling of 21313424420 in words is "twenty-one billion, three hundred thirteen million, four hundred twenty-four thousand, four hundred twenty".