9998861 has 2 divisors, whose sum is σ = 9998862. Its totient is φ = 9998860.

The previous prime is 9998851. The next prime is 9998867. The reversal of 9998861 is 1688999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9517225 + 481636 = 3085^2 + 694^2 .

It is a cyclic number.

It is not a de Polignac number, because 9998861 - 2⁶ = 9998797 is a prime.

It is a Chen prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9998867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999430 + 4999431.

It is an arithmetic number, because the mean of its divisors is an integer number (4999431).

Almost surely, 2^9998861 is an apocalyptic number.

It is an amenable number.

9998861 is a deficient number, since it is larger than the sum of its proper divisors (1).

9998861 is an equidigital number, since it uses as much as digits as its factorization.

9998861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 50.

The square root of 9998861 is about 3162.0975633272. The cubic root of 9998861 is about 215.4352890222.

The spelling of 9998861 in words is "nine million, nine hundred ninety-eight thousand, eight hundred sixty-one".