1278607663 has 2 divisors, whose sum is σ = 1278607664. Its totient is φ = 1278607662.

The previous prime is 1278607661. The next prime is 1278607727. The reversal of 1278607663 is 3667068721.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1278607663 - 2¹ = 1278607661 is a prime.

Together with 1278607661, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278607661) 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, 639303831 + 639303832.

It is an arithmetic number, because the mean of its divisors is an integer number (639303832).

Almost surely, 2^1278607663 is an apocalyptic number.

1278607663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278607663 is an equidigital number, since it uses as much as digits as its factorization.

1278607663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 46.

The square root of 1278607663 is about 35757.6238444335. The cubic root of 1278607663 is about 1085.3732179642.

The spelling of 1278607663 in words is "one billion, two hundred seventy-eight million, six hundred seven thousand, six hundred sixty-three".