9998543531 has 16 divisors (see below), whose sum is σ = 10240147200. Its totient is φ = 9759990240.

The previous prime is 9998543497. The next prime is 9998543537. The reversal of 9998543531 is 1353458999.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 9998543531 - 2¹⁸ = 9998281387 is a prime.

It is a super-2 number, since 2×9998543531² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9998543537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5459786 + ... + 5461616.

It is an arithmetic number, because the mean of its divisors is an integer number (640009200).

Almost surely, 2^9998543531 is an apocalyptic number.

9998543531 is a deficient number, since it is larger than the sum of its proper divisors (241603669).

9998543531 is a wasteful number, since it uses less digits than its factorization.

9998543531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2594.

The product of its digits is 5248800, while the sum is 56.

The square root of 9998543531 is about 99992.7173898179. The cubic root of 9998543531 is about 2154.3300893755.

The spelling of 9998543531 in words is "nine billion, nine hundred ninety-eight million, five hundred forty-three thousand, five hundred thirty-one".