84128647 has 2 divisors, whose sum is σ = 84128648. Its totient is φ = 84128646.

The previous prime is 84128557. The next prime is 84128659. The reversal of 84128647 is 74682148.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84128647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84128677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42064323 + 42064324.

It is an arithmetic number, because the mean of its divisors is an integer number (42064324).

Almost surely, 2^84128647 is an apocalyptic number.

84128647 is a deficient number, since it is larger than the sum of its proper divisors (1).

84128647 is an equidigital number, since it uses as much as digits as its factorization.

84128647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 86016, while the sum is 40.

The square root of 84128647 is about 9172.1669740580. The cubic root of 84128647 is about 438.1753761393.

The spelling of 84128647 in words is "eighty-four million, one hundred twenty-eight thousand, six hundred forty-seven".