998611 has 4 divisors (see below), whose sum is σ = 1002672. Its totient is φ = 994552.

The previous prime is 998561. The next prime is 998617. The reversal of 998611 is 116899.

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 998611 - 2¹¹ = 996563 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (998617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1636 + ... + 2161.

It is an arithmetic number, because the mean of its divisors is an integer number (250668).

2⁹⁹⁸⁶¹¹ is an apocalyptic number.

998611 is a deficient number, since it is larger than the sum of its proper divisors (4061).

998611 is a wasteful number, since it uses less digits than its factorization.

998611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4060.

The product of its digits is 3888, while the sum is 34.

The square root of 998611 is about 999.3052586672. The cubic root of 998611 is about 99.9536785465.

The spelling of 998611 in words is "nine hundred ninety-eight thousand, six hundred eleven".