78778281566 has 8 divisors (see below), whose sum is σ = 119786154384. Its totient is φ = 38849563440.

The previous prime is 78778281557. The next prime is 78778281587. The reversal of 78778281566 is 66518287787.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269788490 + ... + 269788781.

It is an arithmetic number, because the mean of its divisors is an integer number (14973269298).

Almost surely, 2^78778281566 is an apocalyptic number.

78778281566 is a deficient number, since it is larger than the sum of its proper divisors (41007872818).

78778281566 is a wasteful number, since it uses less digits than its factorization.

78778281566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539577346.

The product of its digits is 63221760, while the sum is 65.

The spelling of 78778281566 in words is "seventy-eight billion, seven hundred seventy-eight million, two hundred eighty-one thousand, five hundred sixty-six".