9998978 has 24 divisors (see below), whose sum is σ = 17282160. Its totient is φ = 4302360.

The previous prime is 9998977. The next prime is 9999047. The reversal of 9998978 is 8798999.

It is a super-2 number, since 2×9998978² = 199959122088968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9998971) 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, 7313 + ... + 8571.

It is an arithmetic number, because the mean of its divisors is an integer number (720090).

Almost surely, 2^9998978 is an apocalyptic number.

9998978 is a deficient number, since it is larger than the sum of its proper divisors (7283182).

9998978 is a wasteful number, since it uses less digits than its factorization.

9998978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1310 (or 1291 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 59.

The square root of 9998978 is about 3162.1160636510. The cubic root of 9998978 is about 215.4361293123.

The spelling of 9998978 in words is "nine million, nine hundred ninety-eight thousand, nine hundred seventy-eight".