278845 has 16 divisors (see below), whose sum is σ = 396288. Its totient is φ = 184320.

The previous prime is 278843. The next prime is 278849. The reversal of 278845 is 548872.

It is not a de Polignac number, because 278845 - 2¹ = 278843 is a prime.

It is a Duffinian number.

278845 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 278845.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 957 + ... + 1213.

It is an arithmetic number, because the mean of its divisors is an integer number (24768).

2²⁷⁸⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

278845 is a deficient number, since it is larger than the sum of its proper divisors (117443).

278845 is a wasteful number, since it uses less digits than its factorization.

278845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300.

The product of its digits is 17920, while the sum is 34.

The square root of 278845 is about 528.0577619920. The cubic root of 278845 is about 65.3312479088.

It can be divided in two parts, 27884 and 5, that added together give a square (27889 = 167²).

The spelling of 278845 in words is "two hundred seventy-eight thousand, eight hundred forty-five".