2780165813 has 2 divisors, whose sum is σ = 2780165814. Its totient is φ = 2780165812.

The previous prime is 2780165809. The next prime is 2780165821. The reversal of 2780165813 is 3185610872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2063158084 + 717007729 = 45422^2 + 26777^2 .

It is a cyclic number.

It is not a de Polignac number, because 2780165813 - 2² = 2780165809 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2780165833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1390082906 + 1390082907.

It is an arithmetic number, because the mean of its divisors is an integer number (1390082907).

Almost surely, 2^2780165813 is an apocalyptic number.

It is an amenable number.

2780165813 is a deficient number, since it is larger than the sum of its proper divisors (1).

2780165813 is an equidigital number, since it uses as much as digits as its factorization.

2780165813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 2780165813 is about 52727.2776938085. The cubic root of 2780165813 is about 1406.1238228373.

The spelling of 2780165813 in words is "two billion, seven hundred eighty million, one hundred sixty-five thousand, eight hundred thirteen".