1268978017 has 2 divisors, whose sum is σ = 1268978018. Its totient is φ = 1268978016.

The previous prime is 1268977999. The next prime is 1268978021. The reversal of 1268978017 is 7108798621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1110822241 + 158155776 = 33329^2 + 12576^2 .

It is a cyclic number.

It is not a de Polignac number, because 1268978017 - 2¹¹ = 1268975969 is a prime.

It is a super-2 number, since 2×1268978017² = 3220610415258504578, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1268978047) 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, 634489008 + 634489009.

It is an arithmetic number, because the mean of its divisors is an integer number (634489009).

Almost surely, 2^1268978017 is an apocalyptic number.

It is an amenable number.

1268978017 is a deficient number, since it is larger than the sum of its proper divisors (1).

1268978017 is an equidigital number, since it uses as much as digits as its factorization.

1268978017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 338688, while the sum is 49.

The square root of 1268978017 is about 35622.7177093495. The cubic root of 1268978017 is about 1082.6415724040.

The spelling of 1268978017 in words is "one billion, two hundred sixty-eight million, nine hundred seventy-eight thousand, seventeen".