278438879 has 2 divisors, whose sum is σ = 278438880. Its totient is φ = 278438878.

The previous prime is 278438873. The next prime is 278438887. The reversal of 278438879 is 978834872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278438879 - 2⁸ = 278438623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278438873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139219439 + 139219440.

It is an arithmetic number, because the mean of its divisors is an integer number (139219440).

Almost surely, 2^278438879 is an apocalyptic number.

278438879 is a deficient number, since it is larger than the sum of its proper divisors (1).

278438879 is an equidigital number, since it uses as much as digits as its factorization.

278438879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5419008, while the sum is 56.

The square root of 278438879 is about 16686.4879168745. The cubic root of 278438879 is about 652.9951548506.

The spelling of 278438879 in words is "two hundred seventy-eight million, four hundred thirty-eight thousand, eight hundred seventy-nine".