278361 has 12 divisors (see below), whose sum is σ = 406692. Its totient is φ = 183456.

The previous prime is 278353. The next prime is 278363. The reversal of 278361 is 163872.

It can be written as a sum of positive squares in 2 ways, for example, as 197136 + 81225 = 444^2 + 285^2 .

It is not a de Polignac number, because 278361 - 2³ = 278353 is a prime.

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

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 278361.

It is not an unprimeable number, because it can be changed into a prime (278363) 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 11 ways as a sum of consecutive naturals, for example, 1315 + ... + 1511.

It is an arithmetic number, because the mean of its divisors is an integer number (33891).

2²⁷⁸³⁶¹ is an apocalyptic number.

It is an amenable number.

278361 is a deficient number, since it is larger than the sum of its proper divisors (128331).

278361 is a wasteful number, since it uses less digits than its factorization.

278361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360 (or 357 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 278361 is about 527.5992797569. The cubic root of 278361 is about 65.2934268536.

The spelling of 278361 in words is "two hundred seventy-eight thousand, three hundred sixty-one".