1278863999 has 16 divisors (see below), whose sum is σ = 1507299840. Its totient is φ = 1062388320.

The previous prime is 1278863969. The next prime is 1278864017. The reversal of 1278863999 is 9993688721.

It is a de Polignac number, because none of the positive numbers 2^k-1278863999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278863909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7517 + ... + 51129.

It is an arithmetic number, because the mean of its divisors is an integer number (94206240).

Almost surely, 2^1278863999 is an apocalyptic number.

1278863999 is a deficient number, since it is larger than the sum of its proper divisors (228435841).

1278863999 is an equidigital number, since it uses as much as digits as its factorization.

1278863999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43750.

The product of its digits is 11757312, while the sum is 62.

The square root of 1278863999 is about 35761.2080193049. The cubic root of 1278863999 is about 1085.4457452001.

The spelling of 1278863999 in words is "one billion, two hundred seventy-eight million, eight hundred sixty-three thousand, nine hundred ninety-nine".