21421330220 has 12 divisors (see below), whose sum is σ = 44984793504. Its totient is φ = 8568532080.

The previous prime is 21421330219. The next prime is 21421330223. The reversal of 21421330220 is 2203312412.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1071066511 = 21421330220 / (2 + 1 + 4 + 2 + 1 + 3 + 3 + 0 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 21421330192 and 21421330201.

It is not an unprimeable number, because it can be changed into a prime (21421330223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535533236 + ... + 535533275.

It is an arithmetic number, because the mean of its divisors is an integer number (3748732792).

Almost surely, 2^21421330220 is an apocalyptic number.

21421330220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21421330220 is an abundant number, since it is smaller than the sum of its proper divisors (23563463284).

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

21421330220 is a wasteful number, since it uses less digits than its factorization.

21421330220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071066520 (or 1071066518 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21421330220 its reverse (2203312412), we get a palindrome (23624642632).

The spelling of 21421330220 in words is "twenty-one billion, four hundred twenty-one million, three hundred thirty thousand, two hundred twenty".