2781978218 has 8 divisors (see below), whose sum is σ = 4173210720. Its totient is φ = 1390907980.

The previous prime is 2781978217. The next prime is 2781978257. The reversal of 2781978218 is 8128791872.

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

It is a self number, because there is not a number n which added to its sum of digits gives 2781978218.

It is not an unprimeable number, because it can be changed into a prime (2781978217) by changing a digit.

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, 20963 + ... + 77481.

It is an arithmetic number, because the mean of its divisors is an integer number (521651340).

Almost surely, 2^2781978218 is an apocalyptic number.

2781978218 is a deficient number, since it is larger than the sum of its proper divisors (1391232502).

2781978218 is a wasteful number, since it uses less digits than its factorization.

2781978218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81132.

The product of its digits is 903168, while the sum is 53.

The square root of 2781978218 is about 52744.4614912315. The cubic root of 2781978218 is about 1406.4293096839.

The spelling of 2781978218 in words is "two billion, seven hundred eighty-one million, nine hundred seventy-eight thousand, two hundred eighteen".