20021222210021 has 4 divisors (see below), whose sum is σ = 20026876328844. Its totient is φ = 20015568091200.

The previous prime is 20021222209951. The next prime is 20021222210029. The reversal of 20021222210021 is 12001222212002.

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 4823465745121 + 15197756464900 = 2196239^2 + 3898430^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021222210021 - 2⁴² = 15623175698917 is a prime.

It is a super-3 number, since 3×20021222210021³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021222210029) 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, 2827054100 + ... + 2827061181.

It is an arithmetic number, because the mean of its divisors is an integer number (5006719082211).

Almost surely, 2^{20021222210021} is an apocalyptic number.

It is an amenable number.

20021222210021 is a deficient number, since it is larger than the sum of its proper divisors (5654118823).

20021222210021 is an equidigital number, since it uses as much as digits as its factorization.

20021222210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5654118822.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 20021222210021 its reverse (12001222212002), we get a palindrome (32022444422023).

The spelling of 20021222210021 in words is "twenty trillion, twenty-one billion, two hundred twenty-two million, two hundred ten thousand, twenty-one".