278473649 has 2 divisors, whose sum is σ = 278473650. Its totient is φ = 278473648.

The previous prime is 278473621. The next prime is 278473667. The reversal of 278473649 is 946374872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 232776049 + 45697600 = 15257^2 + 6760^2 .

It is a cyclic number.

It is not a de Polignac number, because 278473649 - 2²⁰ = 277425073 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 278473597 and 278473606.

It is not a weakly prime, because it can be changed into another prime (278473609) 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, 139236824 + 139236825.

It is an arithmetic number, because the mean of its divisors is an integer number (139236825).

Almost surely, 2^278473649 is an apocalyptic number.

It is an amenable number.

278473649 is a deficient number, since it is larger than the sum of its proper divisors (1).

278473649 is an equidigital number, since it uses as much as digits as its factorization.

278473649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2032128, while the sum is 50.

The square root of 278473649 is about 16687.5297452918. The cubic root of 278473649 is about 653.0223345995.

The spelling of 278473649 in words is "two hundred seventy-eight million, four hundred seventy-three thousand, six hundred forty-nine".