278780449 has 2 divisors, whose sum is σ = 278780450. Its totient is φ = 278780448.

The previous prime is 278780441. The next prime is 278780473. The reversal of 278780449 is 944087872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 239630400 + 39150049 = 15480^2 + 6257^2 .

It is a cyclic number.

It is not a de Polignac number, because 278780449 - 2³ = 278780441 is a prime.

It is not a weakly prime, because it can be changed into another prime (278780441) 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, 139390224 + 139390225.

It is an arithmetic number, because the mean of its divisors is an integer number (139390225).

Almost surely, 2^278780449 is an apocalyptic number.

It is an amenable number.

278780449 is a deficient number, since it is larger than the sum of its proper divisors (1).

278780449 is an equidigital number, since it uses as much as digits as its factorization.

278780449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 903168, while the sum is 49.

The square root of 278780449 is about 16696.7197077749. The cubic root of 278780449 is about 653.2620625145.

The spelling of 278780449 in words is "two hundred seventy-eight million, seven hundred eighty thousand, four hundred forty-nine".