998979 has 4 divisors (see below), whose sum is σ = 1331976. Its totient is φ = 665984.

The previous prime is 998969. The next prime is 998983. The reversal of 998979 is 979899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979899 = 3 ⋅326633.

It is a cyclic number.

It is not a de Polignac number, because 998979 - 2⁵ = 998947 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (998909) 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, 166494 + ... + 166499.

It is an arithmetic number, because the mean of its divisors is an integer number (332994).

2⁹⁹⁸⁹⁷⁹ is an apocalyptic number.

998979 is a deficient number, since it is larger than the sum of its proper divisors (332997).

998979 is a wasteful number, since it uses less digits than its factorization.

998979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332996.

The product of its digits is 367416, while the sum is 51.

The square root of 998979 is about 999.4893696283. The cubic root of 998979 is about 99.9659550774.

The spelling of 998979 in words is "nine hundred ninety-eight thousand, nine hundred seventy-nine".