129781489 has 2 divisors, whose sum is σ = 129781490. Its totient is φ = 129781488.

The previous prime is 129781453. The next prime is 129781501. The reversal of 129781489 is 984187921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77580864 + 52200625 = 8808^2 + 7225^2 .

It is an emirp because it is prime and its reverse (984187921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129781489 - 2¹³ = 129773297 is a prime.

It is not a weakly prime, because it can be changed into another prime (129781189) 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, 64890744 + 64890745.

It is an arithmetic number, because the mean of its divisors is an integer number (64890745).

Almost surely, 2^129781489 is an apocalyptic number.

It is an amenable number.

129781489 is a deficient number, since it is larger than the sum of its proper divisors (1).

129781489 is an equidigital number, since it uses as much as digits as its factorization.

129781489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 49.

The square root of 129781489 is about 11392.1678797321. The cubic root of 129781489 is about 506.2957139231.

The spelling of 129781489 in words is "one hundred twenty-nine million, seven hundred eighty-one thousand, four hundred eighty-nine".