998381 has 2 divisors, whose sum is σ = 998382. Its totient is φ = 998380.

The previous prime is 998377. The next prime is 998399. The reversal of 998381 is 183899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 872356 + 126025 = 934^2 + 355^2 .

It is a cyclic number.

It is not a de Polignac number, because 998381 - 2² = 998377 is a prime.

It is a super-2 number, since 2×998381² = 1993529242322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499190 + 499191.

It is an arithmetic number, because the mean of its divisors is an integer number (499191).

2⁹⁹⁸³⁸¹ is an apocalyptic number.

It is an amenable number.

998381 is a deficient number, since it is larger than the sum of its proper divisors (1).

998381 is an equidigital number, since it uses as much as digits as its factorization.

998381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 38.

The square root of 998381 is about 999.1901720894. The cubic root of 998381 is about 99.9460041831.

The spelling of 998381 in words is "nine hundred ninety-eight thousand, three hundred eighty-one".