278891441 has 2 divisors, whose sum is σ = 278891442. Its totient is φ = 278891440.

The previous prime is 278891423. The next prime is 278891449. The reversal of 278891441 is 144198872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 187115041 + 91776400 = 13679^2 + 9580^2 .

It is a cyclic number.

It is not a de Polignac number, because 278891441 - 2²⁶ = 211782577 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 278891392 and 278891401.

It is not a weakly prime, because it can be changed into another prime (278891449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139445720 + 139445721.

It is an arithmetic number, because the mean of its divisors is an integer number (139445721).

Almost surely, 2^278891441 is an apocalyptic number.

It is an amenable number.

278891441 is a deficient number, since it is larger than the sum of its proper divisors (1).

278891441 is an equidigital number, since it uses as much as digits as its factorization.

278891441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 44.

The square root of 278891441 is about 16700.0431436568. The cubic root of 278891441 is about 653.3487463102.

The spelling of 278891441 in words is "two hundred seventy-eight million, eight hundred ninety-one thousand, four hundred forty-one".