1200002121121 has 2 divisors, whose sum is σ = 1200002121122. Its totient is φ = 1200002121120.

The previous prime is 1200002121119. The next prime is 1200002121127. The reversal of 1200002121121 is 1211212000021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1159465936225 + 40536184896 = 1076785^2 + 201336^2 .

It is an emirp because it is prime and its reverse (1211212000021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1200002121121 - 2¹ = 1200002121119 is a prime.

Together with 1200002121119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1200002121127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600001060560 + 600001060561.

It is an arithmetic number, because the mean of its divisors is an integer number (600001060561).

Almost surely, 2^{1200002121121} is an apocalyptic number.

It is an amenable number.

1200002121121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200002121121 is an equidigital number, since it uses as much as digits as its factorization.

1200002121121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1200002121121 its reverse (1211212000021), we get a palindrome (2411214121142).

The spelling of 1200002121121 in words is "one trillion, two hundred billion, two million, one hundred twenty-one thousand, one hundred twenty-one".