278385 has 16 divisors (see below), whose sum is σ = 453696. Its totient is φ = 145728.

The previous prime is 278363. The next prime is 278387. The reversal of 278385 is 583872.

It is not a de Polignac number, because 278385 - 2⁵ = 278353 is a prime.

It is a d-powerful number, because it can be written as 2⁸ + 7³ + 3² + 8 + 8⁶ + 5⁶ .

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

It is a nialpdrome in base 13.

It is a zygodrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (278387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 867 + ... + 1143.

It is an arithmetic number, because the mean of its divisors is an integer number (28356).

2²⁷⁸³⁸⁵ is an apocalyptic number.

It is an amenable number.

278385 is a deficient number, since it is larger than the sum of its proper divisors (175311).

278385 is a wasteful number, since it uses less digits than its factorization.

278385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352.

The product of its digits is 13440, while the sum is 33.

The square root of 278385 is about 527.6220238011. The cubic root of 278385 is about 65.2953033104.

It can be divided in two parts, 2 and 78385, that added together give a palindrome (78387).

The spelling of 278385 in words is "two hundred seventy-eight thousand, three hundred eighty-five".