21222220221212 has 6 divisors (see below), whose sum is σ = 37138885387128. Its totient is φ = 10611110110604.

The previous prime is 21222220221179. The next prime is 21222220221233. The reversal of 21222220221212 is 21212202222212.

It is a super-2 number, since 2×21222220221212² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2652777527648 + ... + 2652777527655.

It is an arithmetic number, because the mean of its divisors is an integer number (6189814231188).

Almost surely, 2^{21222220221212} is an apocalyptic number.

It is an amenable number.

21222220221212 is a deficient number, since it is larger than the sum of its proper divisors (15916665165916).

21222220221212 is a wasteful number, since it uses less digits than its factorization.

21222220221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5305555055307 (or 5305555055305 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 21222220221212 its reverse (21212202222212), we get a palindrome (42434422443424).

The spelling of 21222220221212 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twelve".