998939 has 4 divisors (see below), whose sum is σ = 1004640. Its totient is φ = 993240.

The previous prime is 998927. The next prime is 998941. The reversal of 998939 is 939899.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 939899 = 439 ⋅2141.

It is a cyclic number.

It is not a de Polignac number, because 998939 - 2¹⁶ = 933403 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 998893 and 998902.

It is not an unprimeable number, because it can be changed into a prime (998909) 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, 2579 + ... + 2940.

It is an arithmetic number, because the mean of its divisors is an integer number (251160).

2⁹⁹⁸⁹³⁹ is an apocalyptic number.

998939 is a deficient number, since it is larger than the sum of its proper divisors (5701).

998939 is a wasteful number, since it uses less digits than its factorization.

998939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5700.

The product of its digits is 157464, while the sum is 47.

The square root of 998939 is about 999.4693592102. The cubic root of 998939 is about 99.9646208179.

The spelling of 998939 in words is "nine hundred ninety-eight thousand, nine hundred thirty-nine".