278749 has 8 divisors (see below), whose sum is σ = 311040. Its totient is φ = 248256.

The previous prime is 278743. The next prime is 278753. The reversal of 278749 is 947872.

278749 = 112² + 113² + ... + 130².

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 278749 - 2³ = 278741 is a prime.

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

It is a Duffinian number.

278749 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109 + ... + 754.

It is an arithmetic number, because the mean of its divisors is an integer number (38880).

2²⁷⁸⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

278749 is a deficient number, since it is larger than the sum of its proper divisors (32291).

278749 is a wasteful number, since it uses less digits than its factorization.

278749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899.

The product of its digits is 28224, while the sum is 37.

The square root of 278749 is about 527.9668550203. The cubic root of 278749 is about 65.3237496933.

The spelling of 278749 in words is "two hundred seventy-eight thousand, seven hundred forty-nine".