9981491520 has 1344 divisors, whose sum is σ = 46264836096. Its totient is φ = 1763573760.

The previous prime is 9981491501. The next prime is 9981491581. The reversal of 9981491520 is 251941899.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 9981491520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 212372137 + ... + 212372183.

Almost surely, 2^9981491520 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 9981491520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23132418048).

9981491520 is an abundant number, since it is smaller than the sum of its proper divisors (36283344576).

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

9981491520 is a wasteful number, since it uses less digits than its factorization.

9981491520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 48.

The square root of 9981491520 is about 99907.4147398480. The cubic root of 9981491520 is about 2153.1046921070.

It can be divided in two parts, 9981 and 491520, that added together give a triangular number (501501 = T₁₀₀₁).

The spelling of 9981491520 in words is "nine billion, nine hundred eighty-one million, four hundred ninety-one thousand, five hundred twenty".