21031222220 has 24 divisors (see below), whose sum is σ = 44212243824. Its totient is φ = 8403598016.

The previous prime is 21031222217. The next prime is 21031222231. The reversal of 21031222220 is 2222213012.

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, 536267 + ... + 574146.

It is an arithmetic number, because the mean of its divisors is an integer number (1842176826).

Almost surely, 2^21031222220 is an apocalyptic number.

21031222220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031222220 is an abundant number, since it is smaller than the sum of its proper divisors (23181021604).

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

21031222220 is a wasteful number, since it uses less digits than its factorization.

21031222220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111369 (or 1111367 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21031222220 its reverse (2222213012), we get a palindrome (23253435232).

The spelling of 21031222220 in words is "twenty-one billion, thirty-one million, two hundred twenty-two thousand, two hundred twenty".