9978864 has 80 divisors (see below), whose sum is σ = 31212288. Its totient is φ = 2681856.

The previous prime is 9978833. The next prime is 9978877. The reversal of 9978864 is 4688799.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4839 + ... + 6585.

Almost surely, 2^9978864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9978864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15606144).

9978864 is an abundant number, since it is smaller than the sum of its proper divisors (21233424).

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

9978864 is a wasteful number, since it uses less digits than its factorization.

9978864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1782 (or 1776 counting only the distinct ones).

The product of its digits is 870912, while the sum is 51.

The square root of 9978864 is about 3158.9339974112. The cubic root of 9978864 is about 215.2915748330.

The spelling of 9978864 in words is "nine million, nine hundred seventy-eight thousand, eight hundred sixty-four".