279640 has 16 divisors (see below), whose sum is σ = 629280. Its totient is φ = 111840.

The previous prime is 279637. The next prime is 279641. The reversal of 279640 is 46972.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 279599 and 279608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (279641) 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, 3456 + ... + 3535.

It is an arithmetic number, because the mean of its divisors is an integer number (39330).

2²⁷⁹⁶⁴⁰ is an apocalyptic number.

279640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

279640 is an abundant number, since it is smaller than the sum of its proper divisors (349640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

279640 is a wasteful number, since it uses less digits than its factorization.

279640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7002 (or 6998 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 279640 is about 528.8099847771. The cubic root of 279640 is about 65.3932764678.

It can be divided in two parts, 279 and 640, that added together give a palindrome (919).

The spelling of 279640 in words is "two hundred seventy-nine thousand, six hundred forty".