9991548005481 has 45 divisors (see below), whose sum is σ = 16837389879869. Its totient is φ = 5709190484088.

The previous prime is 9991548005447. The next prime is 9991548005531. The reversal of 9991548005481 is 1845008451999.

The square root of 9991548005481 is 3160941.

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

9991548005481 is a `hidden beast` number, since 9 + 9 + 9 + 1 + 5 + 4 + 80 + 0 + 548 + 1 = 666.

9991548005481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9991548005481 - 2²⁹ = 9991011134569 is a prime.

It is a super-2 number, since 2×9991548005481² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9991548005581) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 464647576 + ... + 464669078.

Almost surely, 2^{9991548005481} is an apocalyptic number.

9991548005481 is the 3160941-st square number.

9991548005481 is the 1580471-st centered octagonal number.

It is an amenable number.

9991548005481 is a deficient number, since it is larger than the sum of its proper divisors (6845841874388).

9991548005481 is an frugal number, since it uses more digits than its factorization.

9991548005481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43040 (or 21513 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 63.

The spelling of 9991548005481 in words is "nine trillion, nine hundred ninety-one billion, five hundred forty-eight million, five thousand, four hundred eighty-one".