4128644491 has 2 divisors, whose sum is σ = 4128644492. Its totient is φ = 4128644490.

The previous prime is 4128644489. The next prime is 4128644551. The reversal of 4128644491 is 1944468214.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4128644491 - 2¹ = 4128644489 is a prime.

Together with 4128644489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (4128644411) 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 as a sum of consecutive naturals, namely, 2064322245 + 2064322246.

It is an arithmetic number, because the mean of its divisors is an integer number (2064322246).

Almost surely, 2^4128644491 is an apocalyptic number.

4128644491 is a deficient number, since it is larger than the sum of its proper divisors (1).

4128644491 is an equidigital number, since it uses as much as digits as its factorization.

4128644491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 221184, while the sum is 43.

The square root of 4128644491 is about 64254.5289532185. The cubic root of 4128644491 is about 1604.2393423305.

The spelling of 4128644491 in words is "four billion, one hundred twenty-eight million, six hundred forty-four thousand, four hundred ninety-one".