278240947 has 4 divisors (see below), whose sum is σ = 282802336. Its totient is φ = 273679560.

The previous prime is 278240929. The next prime is 278240951. The reversal of 278240947 is 749042872.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 278240947 - 2¹¹ = 278238899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278240147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2280603 + ... + 2280724.

It is an arithmetic number, because the mean of its divisors is an integer number (70700584).

Almost surely, 2^278240947 is an apocalyptic number.

278240947 is a deficient number, since it is larger than the sum of its proper divisors (4561389).

278240947 is an equidigital number, since it uses as much as digits as its factorization.

278240947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4561388.

The product of its (nonzero) digits is 225792, while the sum is 43.

The square root of 278240947 is about 16680.5559559626. Note that the first 3 decimals coincide. The cubic root of 278240947 is about 652.8403880599.

The spelling of 278240947 in words is "two hundred seventy-eight million, two hundred forty thousand, nine hundred forty-seven".