9901720890000 has 675 divisors, whose sum is σ = 36844208694007. Its totient is φ = 2481110016000.

The previous prime is 9901720889939. The next prime is 9901720890029. The reversal of 9901720890000 is 980271099.

The square root of 9901720890000 is 3146700.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 22 ways, for example, as 6719521577616 + 3182199312384 = 2592204^2 + 1783872^2 .

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

It is a Duffinian 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 134 ways as a sum of consecutive naturals, for example, 16048169692 + ... + 16048170308.

Almost surely, 2^{9901720890000} is an apocalyptic number.

9901720890000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

9901720890000 is the 3146700-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9901720890000

9901720890000 is an abundant number, since it is smaller than the sum of its proper divisors (26942487804007).

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

9901720890000 is an equidigital number, since it uses as much as digits as its factorization.

9901720890000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1302 (or 644 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The spelling of 9901720890000 in words is "nine trillion, nine hundred one billion, seven hundred twenty million, eight hundred ninety thousand".