9978719 has 2 divisors, whose sum is σ = 9978720. Its totient is φ = 9978718.

The previous prime is 9978659. The next prime is 9978721. The reversal of 9978719 is 9178799.

9978719 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9978719 - 2²⁰ = 8930143 is a prime.

It is a super-2 number, since 2×9978719² = 199149665761922, which contains 22 as substring.

Together with 9978721, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9978739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989359 + 4989360.

It is an arithmetic number, because the mean of its divisors is an integer number (4989360).

Almost surely, 2^9978719 is an apocalyptic number.

9978719 is a deficient number, since it is larger than the sum of its proper divisors (1).

9978719 is an equidigital number, since it uses as much as digits as its factorization.

9978719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 50.

The square root of 9978719 is about 3158.9110465475. The cubic root of 9978719 is about 215.2905320480.

The spelling of 9978719 in words is "nine million, nine hundred seventy-eight thousand, seven hundred nineteen".