20021112222121 has 4 divisors (see below), whose sum is σ = 20349327176644. Its totient is φ = 19692897267600.

The previous prime is 20021112222091. The next prime is 20021112222131. The reversal of 20021112222121 is 12122221112002.

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 1934294042521 + 18086818179600 = 1390789^2 + 4252860^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021112222121 - 2¹⁷ = 20021112091049 is a prime.

It is a super-2 number, since 2×20021112222121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021112222131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164107477170 + ... + 164107477291.

It is an arithmetic number, because the mean of its divisors is an integer number (5087331794161).

Almost surely, 2^{20021112222121} is an apocalyptic number.

It is an amenable number.

20021112222121 is a deficient number, since it is larger than the sum of its proper divisors (328214954523).

20021112222121 is an equidigital number, since it uses as much as digits as its factorization.

20021112222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328214954522.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 20021112222121 its reverse (12122221112002), we get a palindrome (32143333334123).

The spelling of 20021112222121 in words is "twenty trillion, twenty-one billion, one hundred twelve million, two hundred twenty-two thousand, one hundred twenty-one".