278914561 has 2 divisors, whose sum is σ = 278914562. Its totient is φ = 278914560.

The previous prime is 278914543. The next prime is 278914577. The reversal of 278914561 is 165419872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 229704336 + 49210225 = 15156^2 + 7015^2 .

It is a cyclic number.

It is not a de Polignac number, because 278914561 - 2¹⁷ = 278783489 is a prime.

It is not a weakly prime, because it can be changed into another prime (278914511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139457280 + 139457281.

It is an arithmetic number, because the mean of its divisors is an integer number (139457281).

Almost surely, 2^278914561 is an apocalyptic number.

It is an amenable number.

278914561 is a deficient number, since it is larger than the sum of its proper divisors (1).

278914561 is an equidigital number, since it uses as much as digits as its factorization.

278914561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 43.

The square root of 278914561 is about 16700.7353430919. The cubic root of 278914561 is about 653.3667999366.

The spelling of 278914561 in words is "two hundred seventy-eight million, nine hundred fourteen thousand, five hundred sixty-one".