278840 has 16 divisors (see below), whose sum is σ = 627480. Its totient is φ = 111520.

The previous prime is 278827. The next prime is 278843. The reversal of 278840 is 48872.

It is a congruent number.

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

278840 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, 3446 + ... + 3525.

2²⁷⁸⁸⁴⁰ is an apocalyptic number.

278840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

278840 is an abundant number, since it is smaller than the sum of its proper divisors (348640).

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

278840 is a wasteful number, since it uses less digits than its factorization.

278840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6982 (or 6978 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 278840 is about 528.0530276402. The cubic root of 278840 is about 65.3308574192.

The spelling of 278840 in words is "two hundred seventy-eight thousand, eight hundred forty".