21320413220 has 12 divisors (see below), whose sum is σ = 44772867804. Its totient is φ = 8528165280.

The previous prime is 21320413217. The next prime is 21320413229. The reversal of 21320413220 is 2231402312.

It can be written as a sum of positive squares in 2 ways, for example, as 4706234404 + 16614178816 = 68602^2 + 128896^2 .

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: 1066020661 = 21320413220 / (2 + 1 + 3 + 2 + 0 + 4 + 1 + 3 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 21320413192 and 21320413201.

It is not an unprimeable number, because it can be changed into a prime (21320413229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533010311 + ... + 533010350.

It is an arithmetic number, because the mean of its divisors is an integer number (3731072317).

Almost surely, 2^21320413220 is an apocalyptic number.

21320413220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21320413220 is an abundant number, since it is smaller than the sum of its proper divisors (23452454584).

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

21320413220 is a wasteful number, since it uses less digits than its factorization.

21320413220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1066020670 (or 1066020668 counting only the distinct ones).

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

Adding to 21320413220 its reverse (2231402312), we get a palindrome (23551815532).

The spelling of 21320413220 in words is "twenty-one billion, three hundred twenty million, four hundred thirteen thousand, two hundred twenty".