2778216815 has 8 divisors (see below), whose sum is σ = 3636938448. Its totient is φ = 2020521280.

The previous prime is 2778216811. The next prime is 2778216929. The reversal of 2778216815 is 5186128772.

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

It is not a de Polignac number, because 2778216815 - 2² = 2778216811 is a prime.

It is a super-2 number, since 2×2778216815² = 15436977342297488450, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2778216815.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778216811) 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 7 ways as a sum of consecutive naturals, for example, 25256462 + ... + 25256571.

It is an arithmetic number, because the mean of its divisors is an integer number (454617306).

Almost surely, 2^2778216815 is an apocalyptic number.

2778216815 is a deficient number, since it is larger than the sum of its proper divisors (858721633).

2778216815 is a wasteful number, since it uses less digits than its factorization.

2778216815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50513049.

The product of its digits is 376320, while the sum is 47.

The square root of 2778216815 is about 52708.7925777095. The cubic root of 2778216815 is about 1405.7951646017.

The spelling of 2778216815 in words is "two billion, seven hundred seventy-eight million, two hundred sixteen thousand, eight hundred fifteen".