998191 has 4 divisors (see below), whose sum is σ = 1000984. Its totient is φ = 995400.

The previous prime is 998167. The next prime is 998197. The reversal of 998191 is 191899.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 998191 - 2¹¹ = 996143 is a prime.

It is a super-4 number, since 4×998191⁴ (a number of 25 digits) contains 4444 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 998191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 765 + ... + 1606.

It is an arithmetic number, because the mean of its divisors is an integer number (250246).

2⁹⁹⁸¹⁹¹ is an apocalyptic number.

998191 is a deficient number, since it is larger than the sum of its proper divisors (2793).

998191 is a wasteful number, since it uses less digits than its factorization.

998191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2792.

The product of its digits is 5832, while the sum is 37.

The square root of 998191 is about 999.0950905695. The cubic root of 998191 is about 99.9396636025.

The spelling of 998191 in words is "nine hundred ninety-eight thousand, one hundred ninety-one".