278981 has 2 divisors, whose sum is σ = 278982. Its totient is φ = 278980.

The previous prime is 278947. The next prime is 279001. The reversal of 278981 is 189872.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 58081 = 470^2 + 241^2 .

It is a cyclic number.

It is not a de Polignac number, because 278981 - 2⁶ = 278917 is a prime.

It is a super-2 number, since 2×278981² = 155660796722, which contains 22 as substring.

It is a Chen prime.

It is an Ulam number.

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

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 278981.

It is not a weakly prime, because it can be changed into another prime (278911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139490 + 139491.

It is an arithmetic number, because the mean of its divisors is an integer number (139491).

2²⁷⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

278981 is a deficient number, since it is larger than the sum of its proper divisors (1).

278981 is an equidigital number, since it uses as much as digits as its factorization.

278981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 35.

The square root of 278981 is about 528.1865200855. The cubic root of 278981 is about 65.3418674353.

The spelling of 278981 in words is "two hundred seventy-eight thousand, nine hundred eighty-one".