1278666679 has 8 divisors (see below), whose sum is σ = 1354926528. Its totient is φ = 1202522880.

The previous prime is 1278666677. The next prime is 1278666691. The reversal of 1278666679 is 9766668721.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1278666679 - 2¹ = 1278666677 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 (1278666677) 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 7 ways as a sum of consecutive naturals, for example, 5782 + ... + 50899.

It is an arithmetic number, because the mean of its divisors is an integer number (169365816).

Almost surely, 2^1278666679 is an apocalyptic number.

1278666679 is a deficient number, since it is larger than the sum of its proper divisors (76259849).

1278666679 is a wasteful number, since it uses less digits than its factorization.

1278666679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58025.

The product of its digits is 9144576, while the sum is 58.

The square root of 1278666679 is about 35758.4490575304. The cubic root of 1278666679 is about 1085.3899167015.

The spelling of 1278666679 in words is "one billion, two hundred seventy-eight million, six hundred sixty-six thousand, six hundred seventy-nine".