278820 has 36 divisors (see below), whose sum is σ = 846300. Its totient is φ = 74304.

The previous prime is 278819. The next prime is 278827. The reversal of 278820 is 28872.

It can be written as a sum of positive squares in 2 ways, for example, as 97344 + 181476 = 312^2 + 426^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (278827) 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 11 ways as a sum of consecutive naturals, for example, 595 + ... + 954.

2²⁷⁸⁸²⁰ is an apocalyptic number.

278820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

278820 is an abundant number, since it is smaller than the sum of its proper divisors (567480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

278820 is a wasteful number, since it uses less digits than its factorization.

278820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1564 (or 1559 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 278820 is about 528.0340898086. The cubic root of 278820 is about 65.3292954143.

The spelling of 278820 in words is "two hundred seventy-eight thousand, eight hundred twenty".