989979 has 4 divisors (see below), whose sum is σ = 1319976. Its totient is φ = 659984.

The previous prime is 989977. The next prime is 989981. The reversal of 989979 is 979989.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979989 = 3 ⋅326663.

It is an interprime number because it is at equal distance from previous prime (989977) and next prime (989981).

It is a cyclic number.

It is not a de Polignac number, because 989979 - 2¹ = 989977 is a prime.

It is an Ulam number.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (989971) 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, 164994 + ... + 164999.

It is an arithmetic number, because the mean of its divisors is an integer number (329994).

2⁹⁸⁹⁹⁷⁹ is an apocalyptic number.

989979 is a deficient number, since it is larger than the sum of its proper divisors (329997).

989979 is a wasteful number, since it uses less digits than its factorization.

989979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329996.

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

The square root of 989979 is about 994.9768841536. The cubic root of 989979 is about 99.6648446304.

The spelling of 989979 in words is "nine hundred eighty-nine thousand, nine hundred seventy-nine".