2618128781 has 2 divisors, whose sum is σ = 2618128782. Its totient is φ = 2618128780.

The previous prime is 2618128727. The next prime is 2618128811. The reversal of 2618128781 is 1878218162.

2618128781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2178555625 + 439573156 = 46675^2 + 20966^2 .

It is a cyclic number.

It is not a de Polignac number, because 2618128781 - 2¹⁸ = 2617866637 is a prime.

It is a super-2 number, since 2×2618128781² = 13709196627801091922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2618128181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1309064390 + 1309064391.

It is an arithmetic number, because the mean of its divisors is an integer number (1309064391).

Almost surely, 2^2618128781 is an apocalyptic number.

It is an amenable number.

2618128781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2618128781 is an equidigital number, since it uses as much as digits as its factorization.

2618128781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86016, while the sum is 44.

The square root of 2618128781 is about 51167.6536593188. The cubic root of 2618128781 is about 1378.2574064682.

The spelling of 2618128781 in words is "two billion, six hundred eighteen million, one hundred twenty-eight thousand, seven hundred eighty-one".