4000002121 has 2 divisors, whose sum is σ = 4000002122. Its totient is φ = 4000002120.

The previous prime is 4000002091. The next prime is 4000002191. The reversal of 4000002121 is 1212000004.

4000002121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2663076025 + 1336926096 = 51605^2 + 36564^2 .

It is a cyclic number.

It is not a de Polignac number, because 4000002121 - 2⁹ = 4000001609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4000002098 and 4000002107.

It is not a weakly prime, because it can be changed into another prime (4000002191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2000001060 + 2000001061.

It is an arithmetic number, because the mean of its divisors is an integer number (2000001061).

Almost surely, 2^4000002121 is an apocalyptic number.

It is an amenable number.

4000002121 is a deficient number, since it is larger than the sum of its proper divisors (1).

4000002121 is an equidigital number, since it uses as much as digits as its factorization.

4000002121 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 10.

The square root of 4000002121 is about 63245.5699713427. The cubic root of 4000002121 is about 1587.4013325413.

Adding to 4000002121 its reverse (1212000004), we get a palindrome (5212002125).

The spelling of 4000002121 in words is "four billion, two thousand, one hundred twenty-one".