20021211020221 has 4 divisors (see below), whose sum is σ = 20122841533212. Its totient is φ = 19919580507232.

The previous prime is 20021211020201. The next prime is 20021211020243. The reversal of 20021211020221 is 12202011212002.

It is a happy number.

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 17572956224121 + 2448254796100 = 4192011^2 + 1564690^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021211020221 - 2²¹ = 20021208923069 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021211020195 and 20021211020204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021211020201) 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, 50815256200 + ... + 50815256593.

It is an arithmetic number, because the mean of its divisors is an integer number (5030710383303).

Almost surely, 2^{20021211020221} is an apocalyptic number.

It is an amenable number.

20021211020221 is a deficient number, since it is larger than the sum of its proper divisors (101630512991).

20021211020221 is a wasteful number, since it uses less digits than its factorization.

20021211020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101630512990.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20021211020221 its reverse (12202011212002), we get a palindrome (32223222232223).

The spelling of 20021211020221 in words is "twenty trillion, twenty-one billion, two hundred eleven million, twenty thousand, two hundred twenty-one".