978776489 has 2 divisors, whose sum is σ = 978776490. Its totient is φ = 978776488.

The previous prime is 978776473. The next prime is 978776497. The reversal of 978776489 is 984677879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 932264089 + 46512400 = 30533^2 + 6820^2 .

It is a cyclic number.

It is not a de Polignac number, because 978776489 - 2⁴ = 978776473 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (978776459) 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, 489388244 + 489388245.

It is an arithmetic number, because the mean of its divisors is an integer number (489388245).

Almost surely, 2^978776489 is an apocalyptic number.

It is an amenable number.

978776489 is a deficient number, since it is larger than the sum of its proper divisors (1).

978776489 is an equidigital number, since it uses as much as digits as its factorization.

978776489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42674688, while the sum is 65.

The square root of 978776489 is about 31285.4037691701. The cubic root of 978776489 is about 992.8748491345.

The spelling of 978776489 in words is "nine hundred seventy-eight million, seven hundred seventy-six thousand, four hundred eighty-nine".