4228721081 has 4 divisors (see below), whose sum is σ = 4554007332. Its totient is φ = 3903434832.

The previous prime is 4228721071. The next prime is 4228721087. The reversal of 4228721081 is 1801278224.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2446192681 + 1782528400 = 49459^2 + 42220^2 .

It is a cyclic number.

It is not a de Polignac number, because 4228721081 - 2³⁰ = 3154979257 is a prime.

It is a super-2 number, since 2×4228721081² = 35764163961787617122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (4228721087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162643106 + ... + 162643131.

It is an arithmetic number, because the mean of its divisors is an integer number (1138501833).

Almost surely, 2^4228721081 is an apocalyptic number.

It is an amenable number.

4228721081 is a deficient number, since it is larger than the sum of its proper divisors (325286251).

4228721081 is a wasteful number, since it uses less digits than its factorization.

4228721081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325286250.

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 4228721081 is about 65028.6174003415. The cubic root of 4228721081 is about 1617.0980258564.

The spelling of 4228721081 in words is "four billion, two hundred twenty-eight million, seven hundred twenty-one thousand, eighty-one".