278563 has 2 divisors, whose sum is σ = 278564. Its totient is φ = 278562.

The previous prime is 278561. The next prime is 278581. The reversal of 278563 is 365872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278563 - 2¹ = 278561 is a prime.

Together with 278561, it forms a pair of twin primes.

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

It is not a weakly prime, because it can be changed into another prime (278561) 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 as a sum of consecutive naturals, namely, 139281 + 139282.

It is an arithmetic number, because the mean of its divisors is an integer number (139282).

2²⁷⁸⁵⁶³ is an apocalyptic number.

278563 is a deficient number, since it is larger than the sum of its proper divisors (1).

278563 is an equidigital number, since it uses as much as digits as its factorization.

278563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 31.

The square root of 278563 is about 527.7906782049. The cubic root of 278563 is about 65.3092170003.

It can be divided in two parts, 278 and 563, that added together give a square (841 = 29²).

The spelling of 278563 in words is "two hundred seventy-eight thousand, five hundred sixty-three".