20101221012221 has 8 divisors (see below), whose sum is σ = 20402204407680. Its totient is φ = 19800266004288.

The previous prime is 20101221012209. The next prime is 20101221012227. The reversal of 20101221012221 is 12221012210102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20101221012221 - 2¹⁸ = 20101220750077 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20101221012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101221012227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5667941 + ... + 8504586.

It is an arithmetic number, because the mean of its divisors is an integer number (2550275550960).

Almost surely, 2^{20101221012221} is an apocalyptic number.

It is an amenable number.

20101221012221 is a deficient number, since it is larger than the sum of its proper divisors (300983395459).

20101221012221 is a wasteful number, since it uses less digits than its factorization.

20101221012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14193763.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20101221012221 its reverse (12221012210102), we get a palindrome (32322233222323).

The spelling of 20101221012221 in words is "twenty trillion, one hundred one billion, two hundred twenty-one million, twelve thousand, two hundred twenty-one".