200021212121 has 2 divisors, whose sum is σ = 200021212122. Its totient is φ = 200021212120.

The previous prime is 200021212099. The next prime is 200021212211. The reversal of 200021212121 is 121212120002.

Together with next prime (200021212211) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 140418825625 + 59602386496 = 374725^2 + 244136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-200021212121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 200021212096 and 200021212105.

It is not a weakly prime, because it can be changed into another prime (200021212421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100010606060 + 100010606061.

It is an arithmetic number, because the mean of its divisors is an integer number (100010606061).

Almost surely, 2^200021212121 is an apocalyptic number.

It is an amenable number.

200021212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

200021212121 is an equidigital number, since it uses as much as digits as its factorization.

200021212121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 200021212121 its reverse (121212120002), we get a palindrome (321233332123).

It can be divided in two parts, 20002 and 1212121, that multiplied together give a palindrome (24244844242).

The spelling of 200021212121 in words is "two hundred billion, twenty-one million, two hundred twelve thousand, one hundred twenty-one".