9978615 has 12 divisors (see below), whose sum is σ = 17296344. Its totient is φ = 5321904.

The previous prime is 9978613. The next prime is 9978637. The reversal of 9978615 is 5168799.

9978615 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9978615 - 2¹ = 9978613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 221747 = 9978615 / (9 + 9 + 7 + 8 + 6 + 1 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9978613) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 110829 + ... + 110918.

It is an arithmetic number, because the mean of its divisors is an integer number (1441362).

Almost surely, 2^9978615 is an apocalyptic number.

9978615 is a deficient number, since it is larger than the sum of its proper divisors (7317729).

9978615 is a wasteful number, since it uses less digits than its factorization.

9978615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221758 (or 221755 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 9978615 is about 3158.8945851358. The cubic root of 9978615 is about 215.2897841132.

The spelling of 9978615 in words is "nine million, nine hundred seventy-eight thousand, six hundred fifteen".