278345 has 8 divisors (see below), whose sum is σ = 336960. Its totient is φ = 220720.

The previous prime is 278329. The next prime is 278347. The reversal of 278345 is 543872.

It is a happy number.

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

It is not a de Polignac number, because 278345 - 2⁴ = 278329 is a prime.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (278347) 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, 740 + ... + 1050.

It is an arithmetic number, because the mean of its divisors is an integer number (42120).

2²⁷⁸³⁴⁵ is an apocalyptic number.

It is an amenable number.

278345 is a deficient number, since it is larger than the sum of its proper divisors (58615).

278345 is a wasteful number, since it uses less digits than its factorization.

278345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495.

The product of its digits is 6720, while the sum is 29.

The square root of 278345 is about 527.5841165160. The cubic root of 278345 is about 65.2921758224.

The spelling of 278345 in words is "two hundred seventy-eight thousand, three hundred forty-five".