278042251 has 2 divisors, whose sum is σ = 278042252. Its totient is φ = 278042250.

The previous prime is 278042231. The next prime is 278042273. The reversal of 278042251 is 152240872.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278042251 - 2⁹ = 278041739 is a prime.

It is a super-2 number, since 2×278042251² = 154614986682294002, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (278042201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139021125 + 139021126.

It is an arithmetic number, because the mean of its divisors is an integer number (139021126).

Almost surely, 2^278042251 is an apocalyptic number.

278042251 is a deficient number, since it is larger than the sum of its proper divisors (1).

278042251 is an equidigital number, since it uses as much as digits as its factorization.

278042251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 278042251 is about 16674.5989756875. The cubic root of 278042251 is about 652.6849500424.

The spelling of 278042251 in words is "two hundred seventy-eight million, forty-two thousand, two hundred fifty-one".