978809647 has 2 divisors, whose sum is σ = 978809648. Its totient is φ = 978809646.

The previous prime is 978809641. The next prime is 978809659. The reversal of 978809647 is 746908879.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 978809647 - 2⁷ = 978809519 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 978809591 and 978809600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (978809641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489404823 + 489404824.

It is an arithmetic number, because the mean of its divisors is an integer number (489404824).

Almost surely, 2^978809647 is an apocalyptic number.

978809647 is a deficient number, since it is larger than the sum of its proper divisors (1).

978809647 is an equidigital number, since it uses as much as digits as its factorization.

978809647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6096384, while the sum is 58.

The square root of 978809647 is about 31285.9336923161. The cubic root of 978809647 is about 992.8860608779.

The spelling of 978809647 in words is "nine hundred seventy-eight million, eight hundred nine thousand, six hundred forty-seven".