9655721280 has 504 divisors, whose sum is σ = 35680619520. Its totient is φ = 2393763840.

The previous prime is 9655721267. The next prime is 9655721323. The reversal of 9655721280 is 821275569.

9655721280 is a `hidden beast` number, since 9 + 6 + 557 + 2 + 12 + 80 = 666.

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

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, 122224281 + ... + 122224359.

It is an arithmetic number, because the mean of its divisors is an integer number (70794880).

Almost surely, 2^9655721280 is an apocalyptic number.

9655721280 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 9655721280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17840309760).

9655721280 is an abundant number, since it is smaller than the sum of its proper divisors (26024898240).

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

9655721280 is a wasteful number, since it uses less digits than its factorization.

9655721280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The square root of 9655721280 is about 98263.5297554489. The cubic root of 9655721280 is about 2129.4212009294.

The spelling of 9655721280 in words is "nine billion, six hundred fifty-five million, seven hundred twenty-one thousand, two hundred eighty".