21221002220212 has 12 divisors (see below), whose sum is σ = 38751395358816. Its totient is φ = 10149174974840.

The previous prime is 21221002220203. The next prime is 21221002220213. The reversal of 21221002220212 is 21202220012212.

It is a self number, because there is not a number n which added to its sum of digits gives 21221002220212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221002220213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115331533714 + ... + 115331533897.

It is an arithmetic number, because the mean of its divisors is an integer number (3229282946568).

Almost surely, 2^{21221002220212} is an apocalyptic number.

It is an amenable number.

21221002220212 is a deficient number, since it is larger than the sum of its proper divisors (17530393138604).

21221002220212 is a wasteful number, since it uses less digits than its factorization.

21221002220212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230663067638 (or 230663067636 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21221002220212 its reverse (21202220012212), we get a palindrome (42423222232424).

The spelling of 21221002220212 in words is "twenty-one trillion, two hundred twenty-one billion, two million, two hundred twenty thousand, two hundred twelve".