278428 has 12 divisors (see below), whose sum is σ = 497952. Its totient is φ = 136160.

The previous prime is 278413. The next prime is 278437. The reversal of 278428 is 824872.

It is a self number, because there is not a number n which added to its sum of digits gives 278428.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553 + ... + 928.

It is an arithmetic number, because the mean of its divisors is an integer number (41496).

2²⁷⁸⁴²⁸ is an apocalyptic number.

It is an amenable number.

278428 is a deficient number, since it is larger than the sum of its proper divisors (219524).

278428 is a wasteful number, since it uses less digits than its factorization.

278428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532 (or 1530 counting only the distinct ones).

The product of its digits is 7168, while the sum is 31.

The square root of 278428 is about 527.6627710953. The cubic root of 278428 is about 65.2986650259.

The spelling of 278428 in words is "two hundred seventy-eight thousand, four hundred twenty-eight".