218827786778 has 4 divisors (see below), whose sum is σ = 328241680170. Its totient is φ = 109413893388.

The previous prime is 218827786741. The next prime is 218827786819. The reversal of 218827786778 is 877687728812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 218502958249 + 324828529 = 467443^2 + 18023^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54706946693 + ... + 54706946696.

Almost surely, 2^218827786778 is an apocalyptic number.

218827786778 is a deficient number, since it is larger than the sum of its proper divisors (109413893392).

218827786778 is a wasteful number, since it uses less digits than its factorization.

218827786778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109413893391.

The product of its digits is 236027904, while the sum is 71.

The spelling of 218827786778 in words is "two hundred eighteen billion, eight hundred twenty-seven million, seven hundred eighty-six thousand, seven hundred seventy-eight".