1378065281 has 2 divisors, whose sum is σ = 1378065282. Its totient is φ = 1378065280.

The previous prime is 1378065251. The next prime is 1378065287. The reversal of 1378065281 is 1825608731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1240800625 + 137264656 = 35225^2 + 11716^2 .

It is a cyclic number.

It is not a de Polignac number, because 1378065281 - 2¹⁴ = 1378048897 is a prime.

It is a super-2 number, since 2×1378065281² = 3798127837395217922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1378065287) 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, 689032640 + 689032641.

It is an arithmetic number, because the mean of its divisors is an integer number (689032641).

Almost surely, 2^1378065281 is an apocalyptic number.

It is an amenable number.

1378065281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1378065281 is an equidigital number, since it uses as much as digits as its factorization.

1378065281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 1378065281 is about 37122.3016662491. The cubic root of 1378065281 is about 1112.8157500588.

The spelling of 1378065281 in words is "one billion, three hundred seventy-eight million, sixty-five thousand, two hundred eighty-one".