9781659648 has 576 divisors, whose sum is σ = 33116428800. Its totient is φ = 2760376320.

The previous prime is 9781659647. The next prime is 9781659649. The reversal of 9781659648 is 8469561879.

It is an interprime number because it is at equal distance from previous prime (9781659647) and next prime (9781659649).

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×9781659648² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9781659647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 184559590 + ... + 184559642.

It is an arithmetic number, because the mean of its divisors is an integer number (57493800).

Almost surely, 2^9781659648 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 9781659648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16558214400).

9781659648 is an abundant number, since it is smaller than the sum of its proper divisors (23334769152).

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

9781659648 is a wasteful number, since it uses less digits than its factorization.

9781659648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 125 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 63.

The square root of 9781659648 is about 98902.2732195777. The cubic root of 9781659648 is about 2138.6391651021.

It can be divided in two parts, 97816 and 59648, that added together give a cube (157464 = 54³).

The spelling of 9781659648 in words is "nine billion, seven hundred eighty-one million, six hundred fifty-nine thousand, six hundred forty-eight".