9998551 has 4 divisors (see below), whose sum is σ = 10012752. Its totient is φ = 9984352.

The previous prime is 9998543. The next prime is 9998557. The reversal of 9998551 is 1558999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1558999 = 13 ⋅119923.

It is a cyclic number.

It is not a de Polignac number, because 9998551 - 2³ = 9998543 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9998557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5986 + ... + 7471.

It is an arithmetic number, because the mean of its divisors is an integer number (2503188).

Almost surely, 2^9998551 is an apocalyptic number.

9998551 is a deficient number, since it is larger than the sum of its proper divisors (14201).

9998551 is a wasteful number, since it uses less digits than its factorization.

9998551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14200.

The product of its digits is 145800, while the sum is 46.

The square root of 9998551 is about 3162.0485448519. The cubic root of 9998551 is about 215.4330625810.

The spelling of 9998551 in words is "nine million, nine hundred ninety-eight thousand, five hundred fifty-one".