21222210012 has 12 divisors (see below), whose sum is σ = 49518490056. Its totient is φ = 7074070000.

The previous prime is 21222210011. The next prime is 21222210019. The reversal of 21222210012 is 21001222212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21222209973 and 21222210000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222210011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884258739 + ... + 884258762.

It is an arithmetic number, because the mean of its divisors is an integer number (4126540838).

Almost surely, 2^21222210012 is an apocalyptic number.

It is an amenable number.

21222210012 is an abundant number, since it is smaller than the sum of its proper divisors (28296280044).

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

21222210012 is a wasteful number, since it uses less digits than its factorization.

21222210012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768517508 (or 1768517506 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21222210012 its reverse (21001222212), we get a palindrome (42223432224).

The spelling of 21222210012 in words is "twenty-one billion, two hundred twenty-two million, two hundred ten thousand, twelve".