278338984561 has 16 divisors (see below), whose sum is σ = 311117583168. Its totient is φ = 246808972800.

The previous prime is 278338984529. The next prime is 278338984591. The reversal of 278338984561 is 165489833872.

It is a cyclic number.

It is not a de Polignac number, because 278338984561 - 2⁵ = 278338984529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 278338984493 and 278338984502.

It is not an unprimeable number, because it can be changed into a prime (278338984591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2034046 + ... + 2166568.

It is an arithmetic number, because the mean of its divisors is an integer number (19444848948).

Almost surely, 2^278338984561 is an apocalyptic number.

It is an amenable number.

278338984561 is a deficient number, since it is larger than the sum of its proper divisors (32778598607).

278338984561 is a wasteful number, since it uses less digits than its factorization.

278338984561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137232.

The product of its digits is 69672960, while the sum is 64.

The spelling of 278338984561 in words is "two hundred seventy-eight billion, three hundred thirty-eight million, nine hundred eighty-four thousand, five hundred sixty-one".