278789 has 4 divisors (see below), whose sum is σ = 318624. Its totient is φ = 238956.

The previous prime is 278767. The next prime is 278801. The reversal of 278789 is 987872.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 278789 - 2¹² = 274693 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278489) 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 3 ways as a sum of consecutive naturals, for example, 19907 + ... + 19920.

It is an arithmetic number, because the mean of its divisors is an integer number (79656).

2²⁷⁸⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

278789 is a deficient number, since it is larger than the sum of its proper divisors (39835).

278789 is an equidigital number, since it uses as much as digits as its factorization.

278789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39834.

The product of its digits is 56448, while the sum is 41.

The square root of 278789 is about 528.0047348273. The cubic root of 278789 is about 65.3268741590.

The spelling of 278789 in words is "two hundred seventy-eight thousand, seven hundred eighty-nine".