128787877649 has 2 divisors, whose sum is σ = 128787877650. Its totient is φ = 128787877648.

The previous prime is 128787877579. The next prime is 128787877651. The reversal of 128787877649 is 946778787821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107710645249 + 21077232400 = 328193^2 + 145180^2 .

It is a cyclic number.

It is not a de Polignac number, because 128787877649 - 2¹⁶ = 128787812113 is a prime.

Together with 128787877651, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128787877949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64393938824 + 64393938825.

It is an arithmetic number, because the mean of its divisors is an integer number (64393938825).

Almost surely, 2^128787877649 is an apocalyptic number.

It is an amenable number.

128787877649 is a deficient number, since it is larger than the sum of its proper divisors (1).

128787877649 is an equidigital number, since it uses as much as digits as its factorization.

128787877649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 531062784, while the sum is 74.

The spelling of 128787877649 in words is "one hundred twenty-eight billion, seven hundred eighty-seven million, eight hundred seventy-seven thousand, six hundred forty-nine".