2778384645 has 40 divisors (see below), whose sum is σ = 5036537880. Its totient is φ = 1465136640.

The previous prime is 2778384619. The next prime is 2778384667. The reversal of 2778384645 is 5464838772.

It can be written as a sum of positive squares in 4 ways, for example, as 89132481 + 2689252164 = 9441^2 + 51858^2 .

It is not a de Polignac number, because 2778384645 - 2¹⁹ = 2777860357 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2778384591 and 2778384600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2496 + ... + 74585.

It is an arithmetic number, because the mean of its divisors is an integer number (125913447).

Almost surely, 2^2778384645 is an apocalyptic number.

It is an amenable number.

2778384645 is a deficient number, since it is larger than the sum of its proper divisors (2258153235).

2778384645 is an equidigital number, since it uses as much as digits as its factorization.

2778384645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77187 (or 77178 counting only the distinct ones).

The product of its digits is 9031680, while the sum is 54.

The square root of 2778384645 is about 52710.3846030362. The cubic root of 2778384645 is about 1405.8234717099.

The spelling of 2778384645 in words is "two billion, seven hundred seventy-eight million, three hundred eighty-four thousand, six hundred forty-five".