9961316820 has 600 divisors, whose sum is σ = 39458538504. Its totient is φ = 2091059712.

The previous prime is 9961316819. The next prime is 9961316851. The reversal of 9961316820 is 286131699.

It is a happy number.

9961316820 is a `hidden beast` number, since 9 + 9 + 613 + 1 + 6 + 8 + 20 = 666.

9961316820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1867795524 + 8093521296 = 43218^2 + 89964^2 .

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

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 4137 × 4095 × 588.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 199 ways as a sum of consecutive naturals, for example, 50564962 + ... + 50565158.

Almost surely, 2^9961316820 is an apocalyptic number.

9961316820 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 9961316820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19729269252).

9961316820 is an abundant number, since it is smaller than the sum of its proper divisors (29497221684).

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

9961316820 is a wasteful number, since it uses less digits than its factorization.

9961316820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 9961316820 is about 99806.3966887894. The cubic root of 9961316820 is about 2151.6530874044.

The spelling of 9961316820 in words is "nine billion, nine hundred sixty-one million, three hundred sixteen thousand, eight hundred twenty".