278591 has 2 divisors, whose sum is σ = 278592. Its totient is φ = 278590.

The previous prime is 278581. The next prime is 278609. The reversal of 278591 is 195872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278591 - 2¹⁰ = 277567 is a prime.

It is a super-2 number, since 2×278591² = 155225890562, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 278591.

It is not a weakly prime, because it can be changed into another prime (278501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139295 + 139296.

It is an arithmetic number, because the mean of its divisors is an integer number (139296).

2²⁷⁸⁵⁹¹ is an apocalyptic number.

278591 is a deficient number, since it is larger than the sum of its proper divisors (1).

278591 is an equidigital number, since it uses as much as digits as its factorization.

278591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 32.

The square root of 278591 is about 527.8172032058. The cubic root of 278591 is about 65.3114051311.

The spelling of 278591 in words is "two hundred seventy-eight thousand, five hundred ninety-one".