128644487 has 2 divisors, whose sum is σ = 128644488. Its totient is φ = 128644486.

The previous prime is 128644447. The next prime is 128644531. The reversal of 128644487 is 784446821.

It is an a-pointer prime, because the next prime (128644531) can be obtained adding 128644487 to its sum of digits (44).

It is a weak prime.

It is an emirp because it is prime and its reverse (784446821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128644487 - 2¹⁶ = 128578951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128644447) 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, 64322243 + 64322244.

It is an arithmetic number, because the mean of its divisors is an integer number (64322244).

Almost surely, 2^128644487 is an apocalyptic number.

128644487 is a deficient number, since it is larger than the sum of its proper divisors (1).

128644487 is an equidigital number, since it uses as much as digits as its factorization.

128644487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 344064, while the sum is 44.

The square root of 128644487 is about 11342.1553066426. The cubic root of 128644487 is about 504.8128404903.

The spelling of 128644487 in words is "one hundred twenty-eight million, six hundred forty-four thousand, four hundred eighty-seven".