278218139 has 2 divisors, whose sum is σ = 278218140. Its totient is φ = 278218138.

The previous prime is 278218123. The next prime is 278218153. The reversal of 278218139 is 931812872.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 278218139 - 2⁴ = 278218123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 278218096 and 278218105.

It is not a weakly prime, because it can be changed into another prime (278211139) 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, 139109069 + 139109070.

It is an arithmetic number, because the mean of its divisors is an integer number (139109070).

Almost surely, 2^278218139 is an apocalyptic number.

278218139 is a deficient number, since it is larger than the sum of its proper divisors (1).

278218139 is an equidigital number, since it uses as much as digits as its factorization.

278218139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 278218139 is about 16679.8722716932. The cubic root of 278218139 is about 652.8225493358.

The spelling of 278218139 in words is "two hundred seventy-eight million, two hundred eighteen thousand, one hundred thirty-nine".