9998640 has 100 divisors (see below), whose sum is σ = 34749264. Its totient is φ = 2664576.

The previous prime is 9998633. The next prime is 9998641. The reversal of 9998640 is 468999.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9998641) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5709 + ... + 7251.

Almost surely, 2^9998640 is an apocalyptic number.

9998640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9998640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17374632).

9998640 is an abundant number, since it is smaller than the sum of its proper divisors (24750624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9998640 is a wasteful number, since it uses less digits than its factorization.

9998640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1568 (or 1553 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 9998640 is about 3162.0626179758. The cubic root of 9998640 is about 215.4337017898.

The spelling of 9998640 in words is "nine million, nine hundred ninety-eight thousand, six hundred forty".