128905813 has 2 divisors, whose sum is σ = 128905814. Its totient is φ = 128905812.

The previous prime is 128905807. The next prime is 128905837. The reversal of 128905813 is 318509821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79245604 + 49660209 = 8902^2 + 7047^2 .

It is a cyclic number.

It is not a de Polignac number, because 128905813 - 2¹⁷ = 128774741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128905853) 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, 64452906 + 64452907.

It is an arithmetic number, because the mean of its divisors is an integer number (64452907).

Almost surely, 2^128905813 is an apocalyptic number.

It is an amenable number.

128905813 is a deficient number, since it is larger than the sum of its proper divisors (1).

128905813 is an equidigital number, since it uses as much as digits as its factorization.

128905813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 128905813 is about 11353.6695830027. The cubic root of 128905813 is about 505.1544317418.

The spelling of 128905813 in words is "one hundred twenty-eight million, nine hundred five thousand, eight hundred thirteen".