20121002222121 has 20 divisors (see below), whose sum is σ = 30106332805252. Its totient is φ = 13392118901088.

The previous prime is 20121002222093. The next prime is 20121002222147. The reversal of 20121002222121 is 12122220012102.

It is a happy number.

20121002222121 is a `hidden beast` number, since 20 + 1 + 210 + 0 + 222 + 212 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5500014634521 + 14620987587600 = 2345211^2 + 3823740^2 .

It is not a de Polignac number, because 20121002222121 - 2⁵ = 20121002222089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121002222094 and 20121002222103.

It is not an unprimeable number, because it can be changed into a prime (20121002222521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 202566526 + ... + 202665831.

Almost surely, 2^{20121002222121} is an apocalyptic number.

It is an amenable number.

20121002222121 is a deficient number, since it is larger than the sum of its proper divisors (9985330583131).

20121002222121 is an equidigital number, since it uses as much as digits as its factorization.

20121002222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405232982 (or 405232973 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 20121002222121 its reverse (12122220012102), we get a palindrome (32243222234223).

The spelling of 20121002222121 in words is "twenty trillion, one hundred twenty-one billion, two million, two hundred twenty-two thousand, one hundred twenty-one".