21221010112212 has 72 divisors (see below), whose sum is σ = 54176544381960. Its totient is φ = 7003189267200.

The previous prime is 21221010112201. The next prime is 21221010112219. The reversal of 21221010112212 is 21221101012212.

21221010112212 is a `hidden beast` number, since 212 + 210 + 10 + 11 + 221 + 2 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3759426277776 + 17461583834436 = 1938924^2 + 4178706^2 .

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 (21221010112219) 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, 59791614 + ... + 60145482.

It is an arithmetic number, because the mean of its divisors is an integer number (752452005305).

Almost surely, 2^{21221010112212} is an apocalyptic number.

It is an amenable number.

21221010112212 is an abundant number, since it is smaller than the sum of its proper divisors (32955534269748).

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

21221010112212 is a wasteful number, since it uses less digits than its factorization.

21221010112212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370473 (or 370468 counting only the distinct ones).

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

Adding to 21221010112212 its reverse (21221101012212), we get a palindrome (42442111124424).

The spelling of 21221010112212 in words is "twenty-one trillion, two hundred twenty-one billion, ten million, one hundred twelve thousand, two hundred twelve".