278681089697 has 2 divisors, whose sum is σ = 278681089698. Its totient is φ = 278681089696.

The previous prime is 278681089693. The next prime is 278681089747. The reversal of 278681089697 is 796980186872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178549347601 + 100131742096 = 422551^2 + 316436^2 .

It is a cyclic number.

It is not a de Polignac number, because 278681089697 - 2² = 278681089693 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 278681089697.

It is not a weakly prime, because it can be changed into another prime (278681089693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139340544848 + 139340544849.

It is an arithmetic number, because the mean of its divisors is an integer number (139340544849).

Almost surely, 2^278681089697 is an apocalyptic number.

It is an amenable number.

278681089697 is a deficient number, since it is larger than the sum of its proper divisors (1).

278681089697 is an equidigital number, since it uses as much as digits as its factorization.

278681089697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 146313216, while the sum is 71.

The spelling of 278681089697 in words is "two hundred seventy-eight billion, six hundred eighty-one million, eighty-nine thousand, six hundred ninety-seven".