1278614778 has 128 divisors (see below), whose sum is σ = 3250077696. Its totient is φ = 326937600.

The previous prime is 1278614773. The next prime is 1278614819. The reversal of 1278614778 is 8774168721.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 1278614778.

It is not an unprimeable number, because it can be changed into a prime (1278614773) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1349701 + ... + 1350647.

It is an arithmetic number, because the mean of its divisors is an integer number (25391232).

Almost surely, 2^1278614778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1278614778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1625038848).

1278614778 is an abundant number, since it is smaller than the sum of its proper divisors (1971462918).

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

1278614778 is a wasteful number, since it uses less digits than its factorization.

1278614778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1068.

The product of its digits is 1053696, while the sum is 51.

The square root of 1278614778 is about 35757.7233335681. The cubic root of 1278614778 is about 1085.3752312000.

The spelling of 1278614778 in words is "one billion, two hundred seventy-eight million, six hundred fourteen thousand, seven hundred seventy-eight".