20101221222021 has 6 divisors (see below), whose sum is σ = 29035097320710. Its totient is φ = 13400814148008.

The previous prime is 20101221222007. The next prime is 20101221222029. The reversal of 20101221222021 is 12022212210102.

It is a happy number.

20101221222021 is a `hidden beast` number, since 201 + 0 + 1 + 221 + 2 + 220 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16912746725121 + 3188474496900 = 4112511^2 + 1785630^2 .

It is not a de Polignac number, because 20101221222021 - 2⁶ = 20101221221957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20101221221985 and 20101221222003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101221222029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1116734512326 + ... + 1116734512343.

It is an arithmetic number, because the mean of its divisors is an integer number (4839182886785).

Almost surely, 2^{20101221222021} is an apocalyptic number.

It is an amenable number.

20101221222021 is a deficient number, since it is larger than the sum of its proper divisors (8933876098689).

20101221222021 is a wasteful number, since it uses less digits than its factorization.

20101221222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2233469024675 (or 2233469024672 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 20101221222021 its reverse (12022212210102), we get a palindrome (32123433432123).

It can be divided in two parts, 20101 and 221222021, that added together give a palindrome (221242122).

The spelling of 20101221222021 in words is "twenty trillion, one hundred one billion, two hundred twenty-one million, two hundred twenty-two thousand, twenty-one".