278660 has 12 divisors (see below), whose sum is σ = 585228. Its totient is φ = 111456.

The previous prime is 278651. The next prime is 278671. The reversal of 278660 is 66872.

278660 is nontrivially palindromic in base 15.

278660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 217156 + 61504 = 466^2 + 248^2 .

It is a congruent number.

It is an unprimeable number.

278660 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6947 + ... + 6986.

It is an arithmetic number, because the mean of its divisors is an integer number (48769).

2²⁷⁸⁶⁶⁰ is an apocalyptic number.

278660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

278660 is an abundant number, since it is smaller than the sum of its proper divisors (306568).

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

278660 is a wasteful number, since it uses less digits than its factorization.

278660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13942 (or 13940 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 278660 is about 527.8825626974. The cubic root of 278660 is about 65.3167966847.

Subtracting from 278660 its sum of digits (29), we obtain a triangular number (278631 = T₇₄₆).

The spelling of 278660 in words is "two hundred seventy-eight thousand, six hundred sixty".