278611 has 2 divisors, whose sum is σ = 278612. Its totient is φ = 278610.

The previous prime is 278609. The next prime is 278617. The reversal of 278611 is 116872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278611 - 2¹ = 278609 is a prime.

Together with 278609, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (278617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139305 + 139306.

It is an arithmetic number, because the mean of its divisors is an integer number (139306).

2²⁷⁸⁶¹¹ is an apocalyptic number.

278611 is a deficient number, since it is larger than the sum of its proper divisors (1).

278611 is an equidigital number, since it uses as much as digits as its factorization.

278611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 25.

The square root of 278611 is about 527.8361488189. The cubic root of 278611 is about 65.3129679919.

The spelling of 278611 in words is "two hundred seventy-eight thousand, six hundred eleven".