9998981 has 4 divisors (see below), whose sum is σ = 10025472. Its totient is φ = 9972492.

The previous prime is 9998977. The next prime is 9999047. The reversal of 9998981 is 1898999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1898999 = 563 ⋅3373.

It is a cyclic number.

It is not a de Polignac number, because 9998981 - 2² = 9998977 is a prime.

It is a super-2 number, since 2×9998981² = 199959242076722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9998971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12671 + ... + 13436.

It is an arithmetic number, because the mean of its divisors is an integer number (2506368).

Almost surely, 2^9998981 is an apocalyptic number.

It is an amenable number.

9998981 is a deficient number, since it is larger than the sum of its proper divisors (26491).

9998981 is a wasteful number, since it uses less digits than its factorization.

9998981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26490.

The product of its digits is 419904, while the sum is 53.

The square root of 9998981 is about 3162.1165380169. The cubic root of 9998981 is about 215.4361508581.

The spelling of 9998981 in words is "nine million, nine hundred ninety-eight thousand, nine hundred eighty-one".