279989 has 4 divisors (see below), whose sum is σ = 286860. Its totient is φ = 273120.

The previous prime is 279977. The next prime is 279991. The reversal of 279989 is 989972.

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

It can be written as a sum of positive squares in 2 ways, for example, as 70225 + 209764 = 265^2 + 458^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-279989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 279989.

It is not an unprimeable number, because it can be changed into a prime (279919) 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, 3374 + ... + 3455.

It is an arithmetic number, because the mean of its divisors is an integer number (71715).

2²⁷⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

279989 is a deficient number, since it is larger than the sum of its proper divisors (6871).

279989 is an equidigital number, since it uses as much as digits as its factorization.

279989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6870.

The product of its digits is 81648, while the sum is 44.

The square root of 279989 is about 529.1398680878. The cubic root of 279989 is about 65.4204694847.

The spelling of 279989 in words is "two hundred seventy-nine thousand, nine hundred eighty-nine".