278489 has 2 divisors, whose sum is σ = 278490. Its totient is φ = 278488.

The previous prime is 278479. The next prime is 278491. The reversal of 278489 is 984872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 235225 + 43264 = 485^2 + 208^2 .

It is a cyclic number.

It is not a de Polignac number, because 278489 - 2⁸ = 278233 is a prime.

It is a super-2 number, since 2×278489² = 155112246242, which contains 22 as substring.

Together with 278491, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (278459) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139244 + 139245.

It is an arithmetic number, because the mean of its divisors is an integer number (139245).

2²⁷⁸⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

278489 is a deficient number, since it is larger than the sum of its proper divisors (1).

278489 is an equidigital number, since it uses as much as digits as its factorization.

278489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 38.

The square root of 278489 is about 527.7205699989. The cubic root of 278489 is about 65.3034333774.

It can be divided in two parts, 278 and 489, that added together give a palindrome (767).

The spelling of 278489 in words is "two hundred seventy-eight thousand, four hundred eighty-nine".