279561 has 4 divisors (see below), whose sum is σ = 372752. Its totient is φ = 186372.

The previous prime is 279557. The next prime is 279571. The reversal of 279561 is 165972.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 279561 - 2² = 279557 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 279561.

It is not an unprimeable number, because it can be changed into a prime (279511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46591 + ... + 46596.

It is an arithmetic number, because the mean of its divisors is an integer number (93188).

2²⁷⁹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

279561 is a deficient number, since it is larger than the sum of its proper divisors (93191).

279561 is an equidigital number, since it uses as much as digits as its factorization.

279561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93190.

The product of its digits is 3780, while the sum is 30.

The square root of 279561 is about 528.7352834831. The cubic root of 279561 is about 65.3871178884.

The spelling of 279561 in words is "two hundred seventy-nine thousand, five hundred sixty-one".