4222138721 has 2 divisors, whose sum is σ = 4222138722. Its totient is φ = 4222138720.

The previous prime is 4222138643. The next prime is 4222138757. The reversal of 4222138721 is 1278312224.

4222138721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4151998096 + 70140625 = 64436^2 + 8375^2 .

It is a cyclic number.

It is not a de Polignac number, because 4222138721 - 2³⁰ = 3148396897 is a prime.

It is not a weakly prime, because it can be changed into another prime (4222138771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2111069360 + 2111069361.

It is an arithmetic number, because the mean of its divisors is an integer number (2111069361).

Almost surely, 2^4222138721 is an apocalyptic number.

It is an amenable number.

4222138721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4222138721 is an equidigital number, since it uses as much as digits as its factorization.

4222138721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 32.

The square root of 4222138721 is about 64977.9864338685. The cubic root of 4222138721 is about 1616.2585404371.

The spelling of 4222138721 in words is "four billion, two hundred twenty-two million, one hundred thirty-eight thousand, seven hundred twenty-one".