1278666680 has 16 divisors (see below), whose sum is σ = 2877000120. Its totient is φ = 511466656.

The previous prime is 1278666677. The next prime is 1278666691. The reversal of 1278666680 is 866668721.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15983294 + ... + 15983373.

Almost surely, 2^1278666680 is an apocalyptic number.

1278666680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1278666680 is an abundant number, since it is smaller than the sum of its proper divisors (1598333440).

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

1278666680 is a wasteful number, since it uses less digits than its factorization.

1278666680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31966678 (or 31966674 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 50.

The square root of 1278666680 is about 35758.4490715132. The cubic root of 1278666680 is about 1085.3899169844.

The spelling of 1278666680 in words is "one billion, two hundred seventy-eight million, six hundred sixty-six thousand, six hundred eighty".