20122111222121 has 4 divisors (see below), whose sum is σ = 20122120194132. Its totient is φ = 20122102250112.

The previous prime is 20122111222067. The next prime is 20122111222159. The reversal of 20122111222121 is 12122211122102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9576270648025 + 10545840574096 = 3094555^2 + 3247436^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20122111222121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20122111222093 and 20122111222102.

It is not an unprimeable number, because it can be changed into a prime (20122111222621) 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, 2173781 + ... + 6705933.

It is an arithmetic number, because the mean of its divisors is an integer number (5030530048533).

Almost surely, 2^{20122111222121} is an apocalyptic number.

It is an amenable number.

20122111222121 is a deficient number, since it is larger than the sum of its proper divisors (8972011).

20122111222121 is an equidigital number, since it uses as much as digits as its factorization.

20122111222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8972010.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 20122111222121 its reverse (12122211122102), we get a palindrome (32244322344223).

The spelling of 20122111222121 in words is "twenty trillion, one hundred twenty-two billion, one hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".