20021201100221 has 4 divisors (see below), whose sum is σ = 20065011168732. Its totient is φ = 19977391031712.

The previous prime is 20021201100203. The next prime is 20021201100223. The reversal of 20021201100221 is 12200110212002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8066991660025 + 11954209440196 = 2840245^2 + 3457486^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021201100221 - 2¹⁴ = 20021201083837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021201100196 and 20021201100205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021201100223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21905033570 + ... + 21905034483.

It is an arithmetic number, because the mean of its divisors is an integer number (5016252792183).

Almost surely, 2^{20021201100221} is an apocalyptic number.

It is an amenable number.

20021201100221 is a deficient number, since it is larger than the sum of its proper divisors (43810068511).

20021201100221 is an equidigital number, since it uses as much as digits as its factorization.

20021201100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43810068510.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20021201100221 its reverse (12200110212002), we get a palindrome (32221311312223).

The spelling of 20021201100221 in words is "twenty trillion, twenty-one billion, two hundred one million, one hundred thousand, two hundred twenty-one".