1278863969 has 2 divisors, whose sum is σ = 1278863970. Its totient is φ = 1278863968.

The previous prime is 1278863959. The next prime is 1278864017. The reversal of 1278863969 is 9693688721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 736579600 + 542284369 = 27140^2 + 23287^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278863969 - 2²⁴ = 1262086753 is a prime.

It is a super-3 number, since 3×1278863969³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1278863909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639431984 + 639431985.

It is an arithmetic number, because the mean of its divisors is an integer number (639431985).

Almost surely, 2^1278863969 is an apocalyptic number.

It is an amenable number.

1278863969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278863969 is an equidigital number, since it uses as much as digits as its factorization.

1278863969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 59.

The square root of 1278863969 is about 35761.2075998560. The cubic root of 1278863969 is about 1085.4457367125.

The spelling of 1278863969 in words is "one billion, two hundred seventy-eight million, eight hundred sixty-three thousand, nine hundred sixty-nine".