998390 has 8 divisors (see below), whose sum is σ = 1797120. Its totient is φ = 399352.

The previous prime is 998381. The next prime is 998399. The reversal of 998390 is 93899.

It is an interprime number because it is at equal distance from previous prime (998381) and next prime (998399).

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

It is a super-3 number, since 3×998390³ = 2985533316380157000, which contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 998390.

It is not an unprimeable number, because it can be changed into a prime (998399) by changing a digit.

998390 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49910 + ... + 49929.

It is an arithmetic number, because the mean of its divisors is an integer number (224640).

2⁹⁹⁸³⁹⁰ is an apocalyptic number.

998390 is a deficient number, since it is larger than the sum of its proper divisors (798730).

998390 is a wasteful number, since it uses less digits than its factorization.

998390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99846.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 998390 is about 999.1946757264. The cubic root of 998390 is about 99.9463045064.

It can be divided in two parts, 9983 and 90, that multiplied together give a triangular number (898470 = T₁₃₄₀).

The spelling of 998390 in words is "nine hundred ninety-eight thousand, three hundred ninety".