279668561 has 4 divisors (see below), whose sum is σ = 280165872. Its totient is φ = 279171252.

The previous prime is 279668531. The next prime is 279668567. The reversal of 279668561 is 165866972.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-279668561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (279668567) 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, 247811 + ... + 248936.

It is an arithmetic number, because the mean of its divisors is an integer number (70041468).

Almost surely, 2^279668561 is an apocalyptic number.

It is an amenable number.

279668561 is a deficient number, since it is larger than the sum of its proper divisors (497311).

279668561 is an equidigital number, since it uses as much as digits as its factorization.

279668561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497310.

The product of its digits is 1088640, while the sum is 50.

The square root of 279668561 is about 16723.2939638099. The cubic root of 279668561 is about 653.9550270365.

The spelling of 279668561 in words is "two hundred seventy-nine million, six hundred sixty-eight thousand, five hundred sixty-one".