278393 has 2 divisors, whose sum is σ = 278394. Its totient is φ = 278392.

The previous prime is 278387. The next prime is 278413. The reversal of 278393 is 393872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 243049 + 35344 = 493^2 + 188^2 .

It is a cyclic number.

It is not a de Polignac number, because 278393 - 2⁶ = 278329 is a prime.

It is not a weakly prime, because it can be changed into another prime (278353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139196 + 139197.

It is an arithmetic number, because the mean of its divisors is an integer number (139197).

2²⁷⁸³⁹³ is an apocalyptic number.

It is an amenable number.

278393 is a deficient number, since it is larger than the sum of its proper divisors (1).

278393 is an equidigital number, since it uses as much as digits as its factorization.

278393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 32.

The square root of 278393 is about 527.6296049313. The cubic root of 278393 is about 65.2959287721.

The spelling of 278393 in words is "two hundred seventy-eight thousand, three hundred ninety-three".