278539 has 4 divisors (see below), whose sum is σ = 283320. Its totient is φ = 273760.

The previous prime is 278503. The next prime is 278543. The reversal of 278539 is 935872.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 278539 - 2¹⁵ = 245771 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2302 + ... + 2419.

It is an arithmetic number, because the mean of its divisors is an integer number (70830).

2²⁷⁸⁵³⁹ is an apocalyptic number.

278539 is a deficient number, since it is larger than the sum of its proper divisors (4781).

278539 is an equidigital number, since it uses as much as digits as its factorization.

278539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4780.

The product of its digits is 15120, while the sum is 34.

The square root of 278539 is about 527.7679414288. The cubic root of 278539 is about 65.3073413430.

The spelling of 278539 in words is "two hundred seventy-eight thousand, five hundred thirty-nine".