278480557 has 2 divisors, whose sum is σ = 278480558. Its totient is φ = 278480556.

The previous prime is 278480551. The next prime is 278480617. The reversal of 278480557 is 755084872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 270076356 + 8404201 = 16434^2 + 2899^2 .

It is a cyclic number.

It is not a de Polignac number, because 278480557 - 2⁷ = 278480429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278480551) 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, 139240278 + 139240279.

It is an arithmetic number, because the mean of its divisors is an integer number (139240279).

Almost surely, 2^278480557 is an apocalyptic number.

It is an amenable number.

278480557 is a deficient number, since it is larger than the sum of its proper divisors (1).

278480557 is an equidigital number, since it uses as much as digits as its factorization.

278480557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 627200, while the sum is 46.

The square root of 278480557 is about 16687.7367249127. The cubic root of 278480557 is about 653.0277343217.

The spelling of 278480557 in words is "two hundred seventy-eight million, four hundred eighty thousand, five hundred fifty-seven".