4128278121 has 18 divisors (see below), whose sum is σ = 6554448810. Its totient is φ = 2501986080.

The previous prime is 4128278117. The next prime is 4128278137. The reversal of 4128278121 is 1218728214.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 4035425625 + 92852496 = 63525^2 + 9636^2 .

It is not a de Polignac number, because 4128278121 - 2² = 4128278117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (4128278111) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1894356 + ... + 1896533.

It is an arithmetic number, because the mean of its divisors is an integer number (364136045).

Almost surely, 2^4128278121 is an apocalyptic number.

It is an amenable number.

4128278121 is a deficient number, since it is larger than the sum of its proper divisors (2426170689).

4128278121 is a wasteful number, since it uses less digits than its factorization.

4128278121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3790917 (or 3790903 counting only the distinct ones).

The product of its digits is 14336, while the sum is 36.

The square root of 4128278121 is about 64251.6779625248. The cubic root of 4128278121 is about 1604.1918882928.

The spelling of 4128278121 in words is "four billion, one hundred twenty-eight million, two hundred seventy-eight thousand, one hundred twenty-one".