278728 has 8 divisors (see below), whose sum is σ = 522630. Its totient is φ = 139360.

The previous prime is 278717. The next prime is 278741. The reversal of 278728 is 827872.

278728 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in only one way, i.e., 268324 + 10404 = 518^2 + 102^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 278693 and 278702.

It is an unprimeable number.

278728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 17413 + ... + 17428.

2²⁷⁸⁷²⁸ is an apocalyptic number.

It is an amenable number.

278728 is a deficient number, since it is larger than the sum of its proper divisors (243902).

278728 is a wasteful number, since it uses less digits than its factorization.

278728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34847 (or 34843 counting only the distinct ones).

The product of its digits is 12544, while the sum is 34.

The square root of 278728 is about 527.9469670336. The cubic root of 278728 is about 65.3221092292.

The spelling of 278728 in words is "two hundred seventy-eight thousand, seven hundred twenty-eight".