21200104420 has 96 divisors (see below), whose sum is σ = 49587552000. Its totient is φ = 7548710400.

The previous prime is 21200104391. The next prime is 21200104427. The reversal of 21200104420 is 2440100212.

It is a junction number, because it is equal to n+sod(n) for n = 21200104394 and 21200104403.

It is not an unprimeable number, because it can be changed into a prime (21200104427) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2322826 + ... + 2331934.

It is an arithmetic number, because the mean of its divisors is an integer number (516537000).

Almost surely, 2^21200104420 is an apocalyptic number.

21200104420 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 21200104420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24793776000).

21200104420 is an abundant number, since it is smaller than the sum of its proper divisors (28387447580).

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

21200104420 is a wasteful number, since it uses less digits than its factorization.

21200104420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9349 (or 9347 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21200104420 its reverse (2440100212), we get a palindrome (23640204632).

The spelling of 21200104420 in words is "twenty-one billion, two hundred million, one hundred four thousand, four hundred twenty".