9978605 has 36 divisors (see below), whose sum is σ = 15145812. Its totient is φ = 6289920.

The previous prime is 9978601. The next prime is 9978607. The reversal of 9978605 is 5068799.

9978605 = 210² + 211² + ... + 339².

It can be written as a sum of positive squares in 6 ways, for example, as 1044484 + 8934121 = 1022^2 + 2989^2 .

It is not a de Polignac number, because 9978605 - 2² = 9978601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9978601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 41285 + ... + 41525.

It is an arithmetic number, because the mean of its divisors is an integer number (420717).

Almost surely, 2^9978605 is an apocalyptic number.

It is an amenable number.

9978605 is a deficient number, since it is larger than the sum of its proper divisors (5167207).

9978605 is a wasteful number, since it uses less digits than its factorization.

With its successor (9978606) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (286).

9978605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286 (or 266 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 44.

The square root of 9978605 is about 3158.8930023032. The cubic root of 9978605 is about 215.2897121961.

The spelling of 9978605 in words is "nine million, nine hundred seventy-eight thousand, six hundred five".