998842421 has 2 divisors, whose sum is σ = 998842422. Its totient is φ = 998842420.

The previous prime is 998842409. The next prime is 998842433. The reversal of 998842421 is 124248899.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (998842409) and next prime (998842433).

It can be written as a sum of positive squares in only one way, i.e., 812820100 + 186022321 = 28510^2 + 13639^2 .

It is a cyclic number.

It is not a de Polignac number, because 998842421 - 2¹⁰ = 998841397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998842441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499421210 + 499421211.

It is an arithmetic number, because the mean of its divisors is an integer number (499421211).

Almost surely, 2^998842421 is an apocalyptic number.

It is an amenable number.

998842421 is a deficient number, since it is larger than the sum of its proper divisors (1).

998842421 is an equidigital number, since it uses as much as digits as its factorization.

998842421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 331776, while the sum is 47.

The square root of 998842421 is about 31604.4683707858. The cubic root of 998842421 is about 999.6139913498.

The spelling of 998842421 in words is "nine hundred ninety-eight million, eight hundred forty-two thousand, four hundred twenty-one".