21222121101012 has 72 divisors (see below), whose sum is σ = 58226222186496. Its totient is φ = 6478466992704.

The previous prime is 21222121101011. The next prime is 21222121101079. The reversal of 21222121101012 is 21010112122212.

21222121101012 is a `hidden beast` number, since 212 + 221 + 211 + 0 + 10 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222121101011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 178469748 + ... + 178588619.

It is an arithmetic number, because the mean of its divisors is an integer number (808697530368).

Almost surely, 2^{21222121101012} is an apocalyptic number.

It is an amenable number.

21222121101012 is an abundant number, since it is smaller than the sum of its proper divisors (37004101085484).

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

21222121101012 is a wasteful number, since it uses less digits than its factorization.

21222121101012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357058517 (or 357058512 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21222121101012 its reverse (21010112122212), we get a palindrome (42232233223224).

The spelling of 21222121101012 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty-one million, one hundred one thousand, twelve".