1278227778 has 32 divisors (see below), whose sum is σ = 2584229184. Its totient is φ = 421459392.

The previous prime is 1278227759. The next prime is 1278227779. The reversal of 1278227778 is 8777228721.

It is a self number, because there is not a number n which added to its sum of digits gives 1278227778.

It is not an unprimeable number, because it can be changed into a prime (1278227779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 639076 + ... + 641072.

It is an arithmetic number, because the mean of its divisors is an integer number (80757162).

Almost surely, 2^1278227778 is an apocalyptic number.

1278227778 is an abundant number, since it is smaller than the sum of its proper divisors (1306001406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1278227778 is a wasteful number, since it uses less digits than its factorization.

1278227778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3106.

The product of its digits is 1229312, while the sum is 51.

The square root of 1278227778 is about 35752.3115056915. The cubic root of 1278227778 is about 1085.2657161720.

The spelling of 1278227778 in words is "one billion, two hundred seventy-eight million, two hundred twenty-seven thousand, seven hundred seventy-eight".