21243310220 has 24 divisors (see below), whose sum is σ = 48666493008. Its totient is φ = 7724840000.

The previous prime is 21243310213. The next prime is 21243310237. The reversal of 21243310220 is 2201334212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21243310192 and 21243310201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48280031 + ... + 48280470.

It is an arithmetic number, because the mean of its divisors is an integer number (2027770542).

Almost surely, 2^21243310220 is an apocalyptic number.

21243310220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243310220 is an abundant number, since it is smaller than the sum of its proper divisors (27423182788).

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

21243310220 is a wasteful number, since it uses less digits than its factorization.

21243310220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96560521 (or 96560519 counting only the distinct ones).

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

Adding to 21243310220 its reverse (2201334212), we get a palindrome (23444644432).

The spelling of 21243310220 in words is "twenty-one billion, two hundred forty-three million, three hundred ten thousand, two hundred twenty".