278387 has 2 divisors, whose sum is σ = 278388. Its totient is φ = 278386.

The previous prime is 278363. The next prime is 278393. The reversal of 278387 is 783872.

It is a happy number.

278387 is nontrivially palindromic in base 6.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 278387 - 2¹⁰ = 277363 is a prime.

It is a Chen prime.

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

It is a zygodrome in base 6.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 278387.

It is not a weakly prime, because it can be changed into another prime (278347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139193 + 139194.

It is an arithmetic number, because the mean of its divisors is an integer number (139194).

2²⁷⁸³⁸⁷ is an apocalyptic number.

278387 is a deficient number, since it is larger than the sum of its proper divisors (1).

278387 is an equidigital number, since it uses as much as digits as its factorization.

278387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18816, while the sum is 35.

The square root of 278387 is about 527.6239190939. The cubic root of 278387 is about 65.2954596770.

The spelling of 278387 in words is "two hundred seventy-eight thousand, three hundred eighty-seven".