9717256640 has 504 divisors, whose sum is σ = 30839877360. Its totient is φ = 2898395136.

The previous prime is 9717256607. The next prime is 9717256691. The reversal of 9717256640 is 466527179.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 50348384 + ... + 50348576.

Almost surely, 2^9717256640 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 9717256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15419938680).

9717256640 is an abundant number, since it is smaller than the sum of its proper divisors (21122620720).

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

9717256640 is a wasteful number, since it uses less digits than its factorization.

9717256640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 47.

The square root of 9717256640 is about 98576.1464046957. The cubic root of 9717256640 is about 2133.9351852255.

The spelling of 9717256640 in words is "nine billion, seven hundred seventeen million, two hundred fifty-six thousand, six hundred forty".