278961247 has 2 divisors, whose sum is σ = 278961248. Its totient is φ = 278961246.

The previous prime is 278961239. The next prime is 278961269. The reversal of 278961247 is 742169872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278961247 - 2³ = 278961239 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 278961197 and 278961206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278961047) 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, 139480623 + 139480624.

It is an arithmetic number, because the mean of its divisors is an integer number (139480624).

Almost surely, 2^278961247 is an apocalyptic number.

278961247 is a deficient number, since it is larger than the sum of its proper divisors (1).

278961247 is an equidigital number, since it uses as much as digits as its factorization.

278961247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The square root of 278961247 is about 16702.1330074934. The cubic root of 278961247 is about 653.4032524146.

The spelling of 278961247 in words is "two hundred seventy-eight million, nine hundred sixty-one thousand, two hundred forty-seven".