21212222001222 has 32 divisors (see below), whose sum is σ = 48486210469632. Its totient is φ = 6060493406304.

The previous prime is 21212222001163. The next prime is 21212222001227. The reversal of 21212222001222 is 22210022221212.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212222001227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4066173 + ... + 7678424.

It is an arithmetic number, because the mean of its divisors is an integer number (1515194077176).

Almost surely, 2^{21212222001222} is an apocalyptic number.

21212222001222 is an abundant number, since it is smaller than the sum of its proper divisors (27273988468410).

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

21212222001222 is a wasteful number, since it uses less digits than its factorization.

21212222001222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11787612.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21212222001222 its reverse (22210022221212), we get a palindrome (43422244222434).

The spelling of 21212222001222 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty-two million, one thousand, two hundred twenty-two".