4043121221 has 2 divisors, whose sum is σ = 4043121222. Its totient is φ = 4043121220.

The previous prime is 4043121211. The next prime is 4043121253. The reversal of 4043121221 is 1221213404.

4043121221 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., 2401980100 + 1641141121 = 49010^2 + 40511^2 .

It is a cyclic number.

It is not a de Polignac number, because 4043121221 - 2¹⁴ = 4043104837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4043121193 and 4043121202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4043121211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2021560610 + 2021560611.

It is an arithmetic number, because the mean of its divisors is an integer number (2021560611).

Almost surely, 2^4043121221 is an apocalyptic number.

It is an amenable number.

4043121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

4043121221 is an equidigital number, since it uses as much as digits as its factorization.

4043121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 4043121221 is about 63585.5425470287. The cubic root of 4043121221 is about 1593.0848987328.

Adding to 4043121221 its reverse (1221213404), we get a palindrome (5264334625).

The spelling of 4043121221 in words is "four billion, forty-three million, one hundred twenty-one thousand, two hundred twenty-one".