2780688065 has 16 divisors (see below), whose sum is σ = 3478588416. Its totient is φ = 2131464000.

The previous prime is 2780688061. The next prime is 2780688077. The reversal of 2780688065 is 5608860872.

It is not a de Polignac number, because 2780688065 - 2² = 2780688061 is a prime.

It is a super-2 number, since 2×2780688065² = 15464452229666888450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2780688061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73157 + ... + 104466.

It is an arithmetic number, because the mean of its divisors is an integer number (217411776).

Almost surely, 2^2780688065 is an apocalyptic number.

It is an amenable number.

2780688065 is a deficient number, since it is larger than the sum of its proper divisors (697900351).

2780688065 is a wasteful number, since it uses less digits than its factorization.

2780688065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177760.

The product of its (nonzero) digits is 1290240, while the sum is 50.

The square root of 2780688065 is about 52732.2298504435. The cubic root of 2780688065 is about 1406.2118637493.

The spelling of 2780688065 in words is "two billion, seven hundred eighty million, six hundred eighty-eight thousand, sixty-five".