278009243 has 2 divisors, whose sum is σ = 278009244. Its totient is φ = 278009242.

The previous prime is 278009227. The next prime is 278009261. The reversal of 278009243 is 342900872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278009243 - 2⁴ = 278009227 is a prime.

It is a super-4 number, since 4×278009243⁴ (a number of 35 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (278009213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139004621 + 139004622.

It is an arithmetic number, because the mean of its divisors is an integer number (139004622).

Almost surely, 2^278009243 is an apocalyptic number.

278009243 is a deficient number, since it is larger than the sum of its proper divisors (1).

278009243 is an equidigital number, since it uses as much as digits as its factorization.

278009243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 278009243 is about 16673.6091773797. The cubic root of 278009243 is about 652.6591210214.

The spelling of 278009243 in words is "two hundred seventy-eight million, nine thousand, two hundred forty-three".