1000000000121 has 2 divisors, whose sum is σ = 1000000000122. Its totient is φ = 1000000000120.

The previous prime is 1000000000091. The next prime is 1000000000163. The reversal of 1000000000121 is 1210000000001.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1000000000000 + 121 = 1000000^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 1000000000121 - 2¹⁴ = 999999983737 is a prime.

It is not a weakly prime, because it can be changed into another prime (1000000000721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500000000060 + 500000000061.

It is an arithmetic number, because the mean of its divisors is an integer number (500000000061).

Almost surely, 2^{1000000000121} is an apocalyptic number.

It is an amenable number.

1000000000121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000000000121 is an equidigital number, since it uses as much as digits as its factorization.

1000000000121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2, while the sum is 5.

Adding to 1000000000121 its reverse (1210000000001), we get a palindrome (2210000000122).

The spelling of 1000000000121 in words is "one trillion, one hundred twenty-one", and thus it is an aban number.