998842409 has 2 divisors, whose sum is σ = 998842410. Its totient is φ = 998842408.

The previous prime is 998842393. The next prime is 998842421. The reversal of 998842409 is 904248899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 531072025 + 467770384 = 23045^2 + 21628^2 .

It is a cyclic number.

It is not a de Polignac number, because 998842409 - 2⁴ = 998842393 is a prime.

It is not a weakly prime, because it can be changed into another prime (998842489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499421204 + 499421205.

It is an arithmetic number, because the mean of its divisors is an integer number (499421205).

Almost surely, 2^998842409 is an apocalyptic number.

It is an amenable number.

998842409 is a deficient number, since it is larger than the sum of its proper divisors (1).

998842409 is an equidigital number, since it uses as much as digits as its factorization.

998842409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1492992, while the sum is 53.

The square root of 998842409 is about 31604.4681809392. The cubic root of 998842409 is about 999.6139873467.

The spelling of 998842409 in words is "nine hundred ninety-eight million, eight hundred forty-two thousand, four hundred nine".