9616561920 has 576 divisors, whose sum is σ = 39433175040. Its totient is φ = 2173796352.

The previous prime is 9616561897. The next prime is 9616561967. The reversal of 9616561920 is 291656169.

It is a happy number.

9616561920 is a `hidden beast` number, since 9 + 6 + 1 + 6 + 5 + 619 + 20 = 666.

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

It is a super-2 number, since 2×9616561920² (a number of 21 digits) contains 22 as substring.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30723684 + ... + 30723996.

Almost surely, 2^9616561920 is an apocalyptic number.

9616561920 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 9616561920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19716587520).

9616561920 is an abundant number, since it is smaller than the sum of its proper divisors (29816613120).

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

9616561920 is a wasteful number, since it uses less digits than its factorization.

9616561920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477 (or 457 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 9616561920 is about 98064.0704845562. The cubic root of 9616561920 is about 2126.5386352345.

It can be divided in two parts, 9616 and 561920, that added together give a square (571536 = 756²).

The spelling of 9616561920 in words is "nine billion, six hundred sixteen million, five hundred sixty-one thousand, nine hundred twenty".