278720749 has 2 divisors, whose sum is σ = 278720750. Its totient is φ = 278720748.

The previous prime is 278720713. The next prime is 278720759. The reversal of 278720749 is 947027872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 146240649 + 132480100 = 12093^2 + 11510^2 .

It is a cyclic number.

It is not a de Polignac number, because 278720749 - 2⁹ = 278720237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 278720699 and 278720708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278720759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139360374 + 139360375.

It is an arithmetic number, because the mean of its divisors is an integer number (139360375).

Almost surely, 2^278720749 is an apocalyptic number.

It is an amenable number.

278720749 is a deficient number, since it is larger than the sum of its proper divisors (1).

278720749 is an equidigital number, since it uses as much as digits as its factorization.

278720749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 395136, while the sum is 46.

The square root of 278720749 is about 16694.9318357399. The cubic root of 278720749 is about 653.2154278126.

The spelling of 278720749 in words is "two hundred seventy-eight million, seven hundred twenty thousand, seven hundred forty-nine".