278137045721 has 2 divisors, whose sum is σ = 278137045722. Its totient is φ = 278137045720.

The previous prime is 278137045699. The next prime is 278137045723. The reversal of 278137045721 is 127540731872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152987370496 + 125149675225 = 391136^2 + 353765^2 .

It is a cyclic number.

It is not a de Polignac number, because 278137045721 - 2⁶ = 278137045657 is a prime.

Together with 278137045723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (278137045723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139068522860 + 139068522861.

It is an arithmetic number, because the mean of its divisors is an integer number (139068522861).

Almost surely, 2^278137045721 is an apocalyptic number.

It is an amenable number.

278137045721 is a deficient number, since it is larger than the sum of its proper divisors (1).

278137045721 is an equidigital number, since it uses as much as digits as its factorization.

278137045721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 658560, while the sum is 47.

The spelling of 278137045721 in words is "two hundred seventy-eight billion, one hundred thirty-seven million, forty-five thousand, seven hundred twenty-one".