278985 has 16 divisors (see below), whose sum is σ = 510336. Its totient is φ = 127488.

The previous prime is 278981. The next prime is 279001. The reversal of 278985 is 589872.

It is not a de Polignac number, because 278985 - 2² = 278981 is a prime.

It is a d-powerful number, because it can be written as 2¹⁴ + 7³ + 9² + 8 + 8⁶ + 5² .

It is an alternating number because its digits alternate between even and odd.

278985 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (278981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1224 + ... + 1433.

It is an arithmetic number, because the mean of its divisors is an integer number (31896).

2²⁷⁸⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

278985 is a deficient number, since it is larger than the sum of its proper divisors (231351).

278985 is a wasteful number, since it uses less digits than its factorization.

278985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2672.

The product of its digits is 40320, while the sum is 39.

The square root of 278985 is about 528.1903066131. The cubic root of 278985 is about 65.3421797221.

It can be divided in two parts, 2 and 78985, that added together give a palindrome (78987).

The spelling of 278985 in words is "two hundred seventy-eight thousand, nine hundred eighty-five".