998409421 has 8 divisors (see below), whose sum is σ = 1002483000. Its totient is φ = 994344960.

The previous prime is 998409413. The next prime is 998409437. The reversal of 998409421 is 124904899.

It can be written as a sum of positive squares in 4 ways, for example, as 133402500 + 865006921 = 11550^2 + 29411^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 998409421 - 2³ = 998409413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998409481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 286075 + ... + 289543.

It is an arithmetic number, because the mean of its divisors is an integer number (125310375).

Almost surely, 2^998409421 is an apocalyptic number.

It is an amenable number.

998409421 is a deficient number, since it is larger than the sum of its proper divisors (4073579).

998409421 is a wasteful number, since it uses less digits than its factorization.

998409421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4559.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 998409421 is about 31597.6173310584. The cubic root of 998409421 is about 999.4695256467.

The spelling of 998409421 in words is "nine hundred ninety-eight million, four hundred nine thousand, four hundred twenty-one".