21022121221212 has 48 divisors (see below), whose sum is σ = 50379193331712. Its totient is φ = 6818612353920.

The previous prime is 21022121221151. The next prime is 21022121221217. The reversal of 21022121221212 is 21212212122012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022121221217) 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, 55592098 + ... + 55968969.

It is an arithmetic number, because the mean of its divisors is an integer number (1049566527744).

Almost surely, 2^{21022121221212} is an apocalyptic number.

It is an amenable number.

21022121221212 is an abundant number, since it is smaller than the sum of its proper divisors (29357072110500).

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

21022121221212 is a wasteful number, since it uses less digits than its factorization.

21022121221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111561498 (or 111561496 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21022121221212 its reverse (21212212122012), we get a palindrome (42234333343224).

The spelling of 21022121221212 in words is "twenty-one trillion, twenty-two billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twelve".